Mystery 455 H.O. heads
 

I purchased a set of 1971 455 H.O. cylinder heads casting 191 about 25 years ago.A individual was selling these heads and other parts for an acquaintance.These heads are essentially configured like 455-SD heads +.They have pushrod tubes and the valve cover bolts and rocker studs both are through the intake port roof.Combustion chamber size is 92cc that’s after I had hardened valve seats and new stainless valves installed.Chamber was most likely smaller than that before.Also during the purchase the seller then notified me that those heads were special and came out of Pontiac and were not supposed to be sold.I mentioned that I had already mailed the cashiers check a week ago.He then talked the owner into letting them go.These heads are stamped on the back of the head RUSS with looks like a work order number 10750 this is on both heads same location.On the front of the heads are the number 2 stamped four times almost in a rotating cross pattern.Russ Gee was one on engineers on the SD 455 and was also head of the Pontiac Dyno rooms maybe RUSS stamp?And the number 2 stamps may represent Pontiac motor division which Pontiac used on VIN’s etc as a identifier.Or all this could just be a head porters stamps.What do you think?

It looks like you have a set of the heads Dan Whitmore told me about. There were supposed to go on a 10-1 SD 455 with 4 bolt block, forged rods, forged pistons, RAIV valvetrain and cam, pushrod tubes, 850cfm Q jet, aluminum intake. You have a part of history, wanna sell them ?
These are the heads that Chevy nixed because it would have blown away the LS6. Dominating the streets.
Congratulations !
Dan said there were 2 to 4 sets. One of the engineers he knew brought them by his shop to check out.
These heads with larger chambers because the 73 SD 455 heads. Those engineers did not want all their work to go to waste. Pontiacs last gasp.

I plan on keeping them for a while as they have been on my 462 in the 73 T/A.When I purchased them way back when I was just looking for a set of round port heads and these popped up.Other than verifying the 191 casting numbers I never looked for any other identifiers until recently.When I had them freshened up the machine shop was sure curious about them.I wish I would have put them on a flow bench.

A long-time friend and high school buddy of mine has a pair of 191 heads that he got from H.B. Bailey, the early '70s NASCAR driver for Pontiac. They have 72cc chambers and Pontiac engineering stampings. Maybe someday he will let me get a few pictures of them for posting. I won't hold my breath.......I have been trying to buy them from him for years.

Is there a cast date on the heads?


:confused:

Yes.........191

Head casting number on mine is 191.The date is hard to read on mine.Looks like maybe A07 January 7th but the last digit for the year is hard to make out.I will have to try to check it out better.

I bet my 9.7-1 ported iron d ports head, iron intake, iron exhaust manifolds could beat a stock ls6 of the day. Those rectangle ports were huge.
Those are some cool heads there,, 92 cc you could make close to 10-1 on a 455 with a 0 deck and a head gasket of around .035.

Some better pictures would be helpful.

All original service RAIV and early 197 heads didn't have date codes. It'd be a bit odd that the 1970 RASD head would have them.

From what you can see of the intake flange rail they look thin in the pictures. Possibly because the intake side was milled to match the deck. H-O heads could be safely milled to 91-93 CC.

The exhaust ports look heavily ported, a lot more than the heads that were ported by the shop modifying them for the Pontiac engineering department.

It wasn't uncommon for a head porter to install the SD455 sleeves for the same reason Pontiac did. They were available over the counter and easily obtainable.

Not sure why RUSS would have his name stamped on the heads unless he was afraid of loosing them.

The four 2's definitely looks like something the engineering department may have done but they were pretty slap happy with the numbered punches and like to use X a lot.

Unfortunately with the heads installed and engine in the car I’m out of luck on pictures on the intake side.As mentioned under the RUSS stamp there is a series of numbers maybe work order?I have seen machine shops stamp their business name on ported heads such as my D ports that were ported by Dave Bischoff they have SD Perf stamped on them.I have never heard of a company by the name of RUSS doesn’t mean they don’t exist.Or could be a individual head porter.But Russ Gee was the head of Pontiac Experimental engines and involved with the SD-455 program.I read were Pontiac was sending some of there experimental heads to Diamond Engines for head porting.This was in a article on Jim Wangers 1968 Firebird (Black Bird) street racer.

Pontiac engineering U.P.C codes tell the progression of engine development and the time span of usage in many cases.

The code only changed when significant changes were done for the most part.

A few brief examples.

L-74. All high comp 400 4bbl medium performance motors from 68 to 70.

L-78 all low comp 400 4 bbl medium performance motors from 1971 to 1979.

L-67 1968, RA1 D port, RAII round port, so where into the round port era now.

L-67 1969 and 70, RA4 motors except in the F body .
These RA4 engines in 1970 got a LS-1 code

L-75 base line 455 engines.

LS-5 1971-72 455 round port HO.

LS-2 455SD.

So the 455SD was in development as early as 1971

The LS-2 U.P.C code is to me the most likely reason for all the number 2 stamping on your heads there.

Note that once engineering got to making a 455SD 16 preproduction casting that they put the air injection boss back in across the top of the exh ports in case they needed to add a air pump to meet emissions.

Here are molds of an Intake and Exh port from a non ported 455SD production head.

look up the name Russ Flagle...Indy cylinder head. call them and see is that's their stamp. he is no longer alive but maybe somebody there might know

Was Indy cylinder heads even around in the early 70s?

Looks like RA II combustion chambers. Maybe RA IV chambers?

Anyway exterior looks RA II, yet the 191 and no R 96 A reveal design intent for differences. Are they just 191s with high compression?

No nut Russ Flagle was

Russ of Indy Cylinder head fame really hated Pontiacs. It would be a stretch IMO that he did port work on Pontiac heads. I base this opinion on having several Edelbrock Pontiac heads repaired by him and the shop in the 1990's. We took the destroyed by nitrous heads to him and he spent at least half an hour telling us we were morons and idiots for doing anything with a Pontiac engine. Then he tried to scare us away with a very high price to weld them back together. When that didn't work they proceeded to weld up the chambers, weld up 4 destroyed seat areas and honestly make them look like new again. Nicest aluminum repairs I have ever seen. Sometimes you have to put up with allot of abuse to run a Pontiac. But his general disdain for Pontiac engines makes me think it's unlikely he had his hands on your special Pontiac heads. Thinking Russ Gee is more likely. Hope you find out the whole story. Special heads indeed!

The local guy I bought my SR RAIV heads from in the late 80s worked at a Pontiac dealership in parts had a 79 TA he street raced that had some 71 HO heads he said had 72cc chambers from the factory as cheater heads. Solid roller cam Warrior single 4 intake used McCreary sticky dirt tires and would pull the front wheels on the street. Heard the windshield popped out of the T top car on one launch.

I thought I read that it was Waren Brownfield that helped with the development of the 455SD heads, and this would have of course been before AFR.

Just to keep all our Ducks in row here and to reinforce what Paul had in an earlier post the casting number is 197, not 191.
The full part number of the head was 481197.

I have some updates on the 197 455 H.O. cylinder heads..Cleaned up the forward and aft head surfaces along with the date code areas also used my borescope to get a better look at the aft sides by the firewall.Here’s what I discovered.I was incorrect on the info in regards to the number 2 stamps.For some reason I thought that both heads had that.Turns out one head has the number 2 stamps and the other head has number 1 stamps.Both heads are stamped at the same location and font.Both heads due have the RUSS stamped with the same numbers below same font.In another twist I found a much smaller stamp of 12/89 in a different mix match font with what looks like possibly light crude etching.I also was able to read the date codes.L 08 0 on one head.The other head looks maybe like A 07 and last digit looks sort of like a 7 or part of a 0 not sure on that one.Would Pontiac have been casting SRS 197 round port cylinder heads as late as January 1977?

Also let's not forget about what Paul said about date codes. Early production 197 heads didn't have them. It's highly unlikely the SDRA heads that were cancelled in early 1970 would've had them.

Hey Skip.....that's the guy I went to high school with. He got those heads from H.B. Bailey, and as far as I know, he never worked a day in his life! His parents were filthy rich, and he just bought whatever he wanted back then. The 79 T/A is being restored as we speak.
In 1979, he brought said TA to my parents' house on a trailer straight from the dealer with only a few miles on it. Still had the window sticker in place. I recall asking what he was going to do later that evening, and he told me he was going home to pull the motor out of it and put a 455 in its place! True story.

BTW....I need to catchup with you to return some items that I have of yours.

My guess would be yes.... I have an SD455 SR block with a 1977 date code

All 1971 455HO Heads that have a date cast in them are always dated either December 1970 or January 1971 . I’ve been checking the dates for at least 30 years on these heads, we may find a pair with a different date, but probably a service date. I would say there is a zero on the end of the date on these heads

It looks like one head does have a zero on the end.The other head looks like a 7 maybe.I would have never thought that Pontiac would cast a head 6 years after production on a lower volume casting such as a 197 head..

Maybe the opposite of the head casting code?

the 197 casting code looks like 191, maybe the A077 is a A071?

:D

Possibly.... Or maybe it was cast January 7 1977 :D

Jeff his parents did have a pretty nice house when I went to pick up my RAIV heads and he showed me that car. New bare never assembled or had a valve job!

Thanks for the detailed info on the various UPC head codes.On a update I mentioned that I located four number 1’s on the other cylinder head.They are configured just like the number 2’s on the other head.Gor some reason somebody wanted them individually identified.But both heads do have the RUSS stamping with 10750 stamping below.

Those McCreary Oval Star slicks from the 70's were the best! It's too bad they are no longer available.

my understanding is that RPO/UPC codes were reused, and issued by the parent company - not necessarily a divisional thing;
As an example a 1969 Chevelle could have been ordered with an L78, and so could a same year GTO;
In the case of the GTO it was the ‘base’ 400/4bbl engine - for the Chevelle it was much more special.

Here is my correction of the engine codes which Pontiac used, and what I removed from above:

L-30: 350/2bb 1968-1977

L-65: 350HO 1968/69; 350/4bbl 1974-1977; best 350 you could get for the given year

L-67: 400 ‘Ram Air’; 1967-1968.5 ‘D-port’; 1968.5-1970 ‘round-port’; the best 400 you could get for the given year

L-74: 400HO 1967-1969(?); “RAIII” 1969-1970; one step down from the L-67

L-75: 455/4bbl 1970-1976; “bread and butter” 455 performance engine for which ever model year

L-78: 400/4bbl 1967-1979; “bread and butter” 400 performance engine for which ever model year

LS1; (purported) RAIV-SD 1970; did not pass pre-production stage.

No idea where you are located or where you bought the heads --
- but if anywhere near Greensboro NC area -
- they were likely done for Russ that worked at Motor Bearings on Patterson Ave.

Longshot
He was always building HiPo Poncho stuff for a while in the 80s and early 90s

I had friend working ,going to school GMI he was working in dyno room at Pontiac. He gave me the dyno sheets from the SD455 about 1976. I've given them out to many people over the years.( he ask me to keep them to myself then at 1st POCI orange county I gave them to Pete for the first time) they are dated1970 at the top. I do have nos push rod tubes. Interesting heads

Thanks for the info.Im not anywhere near NC.I bought the heads 24 years ago.They were purchased out of state maybe Florida but not one hundred percent sure on that.I was trying to remember were I seen them advertised might have been the old Classical Pontiac classified section on line or maybe eBay.I know I paid cashiers check.Its been a long time ago.

I’m going with a cast mistake and should be A071

I found a rather lengthy article in which Herb Adams discusses the 303,,366 and 455-SD,Tom Neil,Jeff Young and Russ Gee are all in the article also.In the article they say that the sent heads out to three different head porting companies.Two located in California and one in Florida.One being Air Flow Research.Herb mentions that they sent some Ram Air IV heads to these companies and told them to do the works on them.They mention that the 455-SD was a clean sheet design using what they had discovered at Air Flow Research..Also mentions that it was Russ Gees idea to take what they learned on the 303,366 race programs and use it in the 455-SD.

It does look a little funky.When it’s blown up it looks like the horizontal portion is about half of the other also the vertical has more radius to it.

Thinking back when I acquired the heads they were fully assembled with what appeared to be factory hardware.Valves appeared to be of OEM variety.Still had the factory 3/8 bottle neck rocker studs with factory stamped rocker arms.These 197 H.O. heads were ported to 455 SD specs such as pushrod tubes,raised roof on intake ports were rocker stud and valve cover holes were exposed and exhaust port was configured to SD also.So if a private individual were to have taken these heads to a machine shop/head porter looking to increase head flow and performance why would they use factory OE hardware and also not get the exhaust cross overs filled..The cylinder heads are marked as a matching pair as both heads have the RUSS and 10750 stamping on them.So then why have the heads individually marked with the four number 2’s and four number 1’s?These stamps are not free hand stamps looks like a special made gang stamp to fit in that location.One possibility that sounds plausible to me is that they were individually stamped in those exact locations for identification for testing.Maybe flow bench testing then they could record and document each individual cylinder head.Pontiac not only had their dyno test facility but also had their own flow bench.

That's good information. Pontiac Engineering sent heads to AFR, Crane and Mullins. They were original service RAIV heads. The AFR were the clear winners and they were too busy to supply heads for Pontiac, so with AFR blessing they had Diamond Elkins copy AFR's work. It forged a long relationship with Elkins and later they helped develop the Turbo Regal heads. I've had heads and blocks come through my shop that came from the Pontiac Engineering Department. They had all kinds of numbers stamped on them. A lot more than just four twos and four ones. They really liked X and /. I've also worked on Pontiac round port heads that were worked on by Crane, Mullins and Elkins. All of them have the company name stamped on the ends of the heads. NONE of them had pushrod tubes installed.

There's a paper floating around written by a Pontiac engineer that used the AFR/Elkins head on the Pontiac flow bench that suggests the pushrod tubes and the port design changes at the flange for the SD head. Both those changes are incorporated into the SD heads.

The Unicorn 1970 RASD head was cancelled long before your heads were cast. We have a knowledgeable member here saying all 197's were cast around the same time. If Russ wanted to work with a special head why would he go with a 197 head? Why not the improved 7F6 head? He would full well know a RAIV head or SD head would kick the crap out of a 197 head. We all know that and he had access to a crap ton more information than we do.

If he used one of the RASD Unicorn heads would we assume the wrong later dates were added just to confuse the issue? Unfortunately we have no pictures of your intake ports but we know your exhaust port exits have been hogged out much farther than anything Crane, AFR, Elkins or Mullins was doing back in the day.

Really, I think it's more plausible these heads were done by these guys rather than a secret Pontiac back door operation..... JMHO

If you actually go back and read my original post you will see that I never mentioned the year 1970 RASD cylinder head I don’t know were you came up with that.So no confusion on my end.
I would think that if one was developing the 455 SD head that the 1971 455 H.O. head would be a good one to use to get porting flow data.It has the same 111 cc combustion chamber as the 455 SD and the 71 455 H.O. 197 head has better exhaust flow than the 1972 7F6 head right of the bat.The 7F6 head has a restrictive exhaust port (information from page 47 Pontiac Engine Design & Blueprint Assembly book).Craig Hendrickson& Kern Osterstock.You say that the 7F6 head was a improved.In what area just curious.Also you mentioned that the heads being disused just have four 2’s and four 1’s.I guess you didn’t see the RUSS or work order numbers stamped that was mentioned.If you have some pictures of any of the numerous heads that came through from Pontiac engineering myself and others would love to see them for future reference.You mentioned about the exhaust ports on the 197 heads being discussed as all hogged out.I would think gasket matched but not much if any beyond that.I am using stock Ram Air Restoration exhaust manifolds with factory metal gaskets with no overhang in the ports.Also using a untouched factory 1971 455 H.O. intake using stock port Felpro 1233 gaskets.

Here’s what I would call hogged out!

Interesting maybe another possibility.Good info.

Too bad they were made / gasket matched that big at the exh flange .
There’s no need for that at all and it only makes for reversion and delaying the cam from coming into its power band.

I'm well aware you mentioned RUSS and a work order number. None of that indicates those numbers mentioned would have matched up with numbers from Pontiac Engineering. Only the twos and fours look like something they might've done.

The SD head was turned over to production about the time your heads were cast. There'd be zero time to send them to be ported, returned, evaluated and Dyno tested. I brought up the RASD head as that's the only 197 head made with an 87 CC chamber. You mentioned your heads were probably smaller than the measured 92cc . I figured if they're not milled 111 cc chambers the only other option is the RASD. Or am I missing something?

If your heads have been matched to a factory exhaust gasket, it's an optical illusion they look larger. If your intake ports match a 1233 gasket they're smaller than an SD455 intake port.

The 7F6 is a redesign casting made with a different casting process. It's more consistent, has better water jackets, has induction hardened seats, a short turn which will work better than a 197 head and possibly an over the counter IV head, for competition use. The exhaust is not a restriction what so ever compared to a 197 head. But regardless the engineering department knew a ported RAIV head kicked azz. They felt like the SD head was better than the IV head. I'm quite certain if Russ wanted to put his name on a pair of heads it would've been a top shelf head..... Not a modified 197 when he knew he had several better choices.

It seems more likely RUSS racing engines in Florida stamped their name and order number on those heads. Especially since they came from Florida and RUSS operated in that State. It'd also explain the 3/8 studs .... GM engineering was using the 7/16 RAIV parts on their dyno engines, it'd be likely Russ would've continued the practice.

Those particular Ram Air IV heads are not mine.Just a random picture of a Hogged out head!lol

I mentioned that these heads may have been purchased out of Florida.I don’t remember for sure it’s been 24 years ago.I never stated that these heads for sure came out of Pontiacs back door only the comment that the individual made during the purchase.I stated maybe they did or maybe somebody just had them ported.The Felpro 1233 does work on the 455 SD or 455 H.O. and Ram Air IV.People on this forum have used them on the 455 SD intake side.

Understood..... The 1233 is smaller than a factory SD-455 port. It is the correct size for a RAIV/HO port.

You seemed to think Russ Gee may have been involved with your heads. I suggested, it seems more likely RUSS racing heads were involved with your heads. They even spell RUSS the same way it's stamped on your heads.

That is good info that you found on Russ Barfield.👍I need to look up more info maybe some one out there has a known set ported by him with those similar stamping.The Russ Gee reference was just a another possibility since he was involved with engine development etc.If another set of heads surface that would answer the question.If you look at the specs on the Felpro 1233 gasket there is only .02 differences in the height.The Felpro 1233 is actually talller than the RA IV port.

The 1233 works fine on the RAIV if all one wants to do is seal ports. If one likes to do chit wrong and trim gaskets it can be used on the SD455. The Fel-pro MS 90123 has the same dimensions as the factory RAIV gasket and it's a better choice. SCE offers the correct dimension gasket for the SD455, no need to trim or massage the bolt holes. But all the gaskets are missing the square forward corner the factory gaskets used.

You could look for RAV heads with RUSS stamped on them. I'd think he did more work with those and that might solve your mystery.