[Goat4three]

currently i have a 67 gto with 3.55 gears and a turbo 400. i checked the engine code and i have a '73 400 with 4X heads. i want to go mid 12's in the quarter and keep the pistons, crank, and rods stock (as this is what i believe they currently are). i just pulled the motor today and i am about to disassemble the top end. i was thinking about using the edelbrock performer rpm "total performance package" with the heads, intake, carb, cam, and headers by doug but there are a few specs i'm not too sure about.

one being, what is the difference between the the two available heads, i know the difference in the combustion chamber size but which size do i want. the edelbrock catalogue claims some 422 h.p. using a "stock" 400 with the 72cc heads but will i have gas issues (i want to run pump gas)?
will the 87cc heads perform like i want (i know either will be a vast improvement over the 114cc 4X's i currently have, but for $2,000 dollars i want the best for my application.)


the second question is with the cam. the numbers on the cam seem to be consistant with the ram air IV cam which i thought would be a good choice but after searching some of the threads on this forum i'm beginning to think otherwise.

i have noticed on alot of the shoot outs in H.P.P. that not alot of people use the edelbrock cam. most use crower or lunati or comp. i assume there is a great reason for this but i'm not too knowledgable about cam #'s and related stuff.

spending money is one thing...but wasting it on components that don't work together is another.

[Ron H]

The Edelbrock performer RPM package is a clone of the RA1V system. The heads are an aluminum version, which 72 cc heads should not be a problem with your 400 as they are aluminum. The cam is also the RA1V cam. The RPM intake is different as it has longer runners, it is an inch taller than a stock intake and gives you more top end with higher rpm. You may want to look around other shops before going to edelbrock. www.krepower.com is one.KRE has an aluminum D port head that is a newer design and is supposed to be great. They also sell edelbrock heads. These KRE heads are new technology and they could also advise you on a newer technology cam etc. The RA1V stuff was developed 36 or more years ago, though great back then, today there is better products. Also once you get your engine apart you may need to do some machining and since you will be in there, why not upgrade the bottom end?

[johnsma22]

First of all, to the board. I went with the 87cc E-heads for my 400 project only because I plan on swapping all my goodies onto a 455 next year. 72cc heads would not be a good idea on a 455 for the street on pump gas. However, if you are planning on staying with your 400, you can, and should go with the 72cc E-heads. They will yield a CR of about 10:1 or so, depending on whether you have the block bored or zero decked. The aluminum heads allow you to run a higher CR than iron heads, due to aluminums ability to shed heat more quickly than cast iron. Also, I bought my heads bare and had my builder select and install the proper valves, seals and springs specifically for my application. They were also ported. You don't nesessarily have to go that route. The E-heads are quite good right out of the box.

On the subject of cams, there are varied opinions as to brand and grinds here. I have never heard anything bad about Edelbrocks cams, in fact, I have not really heard anything at all about Edelbrocks cams! That speaks volumes in and of itself. I run a custom ground Comp Cams hydraulic roller. It was a little on the expensive side but it was worth it to me. It was recommended to me by my builder for my application. 224/230 @ .050" duration .525"/.565" lift with 1.5 ratio Harland sharp roller rockers. A duration and lift somewhere in that ball park would be good for your E-headed 400. I'm sure you will get some more info and suggestions on cams from others more knowledgable than myself, but the numbers should be pretty close to what I have.

I also run a port matched Edelbrock Performer RPM manifold on my 400 with a 750 Speed Demon carb w/ manual secondaries. A lot of guys here love the factory Q-jet. A properly prepared Q-jet, from what I hear, is pretty hard to beat, in the performance and economy department. I already had bought my Demon when I learned this fact, so I decided just to run with the Demon for now. It runs real strong with no hesitations or bogs whatsoever. I don't really have that much experience with carbs, so again, others more knowledgable that I will chime in and help you out. Do a search for Cliff Ruggles, he is the resident Q-jet guru around here and could build you a Q-jet that would perfectly match your needs. From what I have read, he is a great guy and you would not be sorry.

One thing I can tell you about carbs is that the Edelbrock AFB clones are not too well thought of here. From personal experience, I hated mine. I had several good carb tuners try with out success to get it to run right throughout the entire rpm range. It seemed like if we got it dialed in for a good idle, acceleration and WOT suffered and when we got it to run well at WOT it would not idle properly. Maybe I'm wrong but I don't think so.

As far as the Dougs headers go, I don't think you can go wrong with that choice. I chose to run H.O Ram Air manifolds due to problems associated with fitment on 2nd gen 4 speed firebirds. I don't feel that I gave up a whole lot doing so though. I don't think you will have fitment issues with headers on your GTO.

So the moral of my LONGWINDED story, and I think most would agree, is to not put all your eggs in one Edelbrock basket. Take your time, ask some more questions and spend your money wisely, the first time.

You have definitely come to right place. There are more knowledgable, passionate, Pontiac fanatics here than anywhere else on the planet. Good luck and have fun with this! Like the above post says, shop around for some good Pontiac shops. Here is a link to Butler Performance, one of the best. http://www.jbp-pontiac.com/services.html
They are a great bunch of guys and will gladly take the time to answer all your questions.


Also here is a link to my website so you can hear what your 400 might just wound like when you are done! Take a listen also to the video titled "old motor", it is what my stock 400 sounded like before the rebuild.
http://homepage.mac.com/johnsma22/iMovieTheater33.html

John

[Will]

I can understand being on a budget and not wanting to rebuild a solid bottom end if you don't have to. However, you need to consider your overall goals for this car and engine. Are you going to be happy getting a nice power bump from your mods and don't plan to do anything beyond that or will you eventually build a bigger engine that might need different heads?

Limiting myself to just the question you asked, I would strongly warn you not to extend the operating RPM range of a stock shortblock unless you like picking internal engine parts up off the street. The stock connecting rod bolts are weak and *will fail* if you start revving that thing beyond 5500 RPM on a consistent basis. A rev limiter of some sort is a smart investment.

If I was you, I'd give the good folks at KRE a call. I think a set of their D-port aluminum heads would be just the ticket. Much better port and chamber design for a street car than the E-heads. The only problem might be getting a combustion chamber size that will work for you but I'm hearing rumblings that they're offering a little larger chamber now.

A cam with duration in the mid 220 @ .050" range would work great. If you go with the KRE heads, it would also be a good idea to run a high ratio rocker arm to speed up valve motion and increase lift for the same duration. What is it that roller cams do as compared to flat tappet cams again? Oh yeah, they speed up valve motion and increase lift for the same duration...

With a stock bottom end and a rev limit of 5500 RPM or so it will be very possible to put your car into the mid 12s with the gears you have, good heads, the right cam, intake, carb and torque converter.

The RPM intake would be my first choice, followed by a Torker II or the new Tomahawk topped off with an 800 Q-jet built by someone like Cliff or a Holley 750 mechanical secondaries.

Don't overlook the torque converter. Critical to good performance. The better quality (more $$) converters have high-sounding stall speeds that you need for best performance (about 3000 RPM would be close to ideal for the abovementioned combo) but are very well coupled below the rated stall speed for good efficiency and near-stock operation in normal driving. My 11" Coan flashed to 3300 or so behind my 428 yet the car would still creep forward at stoplights if I took my foot of the brake and accelerated easily with only moderate throttle openings. There are even better converters out there than this for our Pontiacs.

[Goat4three]

o.k.....so it seems that the e-heads are a decent choice but with apparently older technology due to the fact that they are modeled after the '70 model RA IV heads. also, it looks like a common opinion that the only thing edelbrock has to offer that is worth having is the heads and intakes (for pontiac). i have visited the KRE and JBP websites and now i have a few more questions to throw into the mix:

how do the KRE heads compare to the e-heads as far as reliability and engineering? can one expect to get 50,000+ miles out of the street version and do they have such things as stainless helicoiled threads etc....

the prices seemed comparable enough. just from looking at the website and not knowing exactly what i'm looking at it seems they are comparing apples to apples with the bolt on right out of the box versions.

secondly, if i buy either head from KRE will they be able to point me in the right direction for cam/intake combo?

lastly, i agree with all of you about rebuilding the bottom end of my motor. the reason i probably won't at this time is that it currently has less than 5,000 miles on it. the only real reason i pulled it to begin with is that i put a hole in the oil pan back in 1991 while my dad owned the car. i had the engine out of my '71 GTO and needed a ride for school. anyway, there was a classmate that had a '79 pace car edition mustang who just wouldn't shut up....long story short, the roads in Mississippi aren't the greatest and well i found out where the bottom limits of the suspension travel were as the oil pan hit the road. i smoked the mustang by 10 car lengths or so but had to call dear ol' dad and tell him to bring some oil, sheet metal screws and some JB Weld to school. the car has basically just been run here and there since but no real miles have been put on the 54,000 mile body.

thanks for the cool welcome to the forum and all the great info....killer link to the trans am page. if my car runs half as good as your car sounds...me, wifey, and son will be quite happy.

[Money Pit]

Call Jeff at KRE, he a super nice guy to talk to and deal with, he will set you up with the right combo. Go with the alum. d-ports, you won't be sorry. I'm not, it's one of the best investments i've made, there heads are a great product! Why do you need s.s. helicoils? Are you worried about cross threading? Just use a header stud kit, you won't have to worry about cross threading when you're installing the headers.

[Goat4three]

thanks for the contact info.


i just like the idea of threading steel bolts into steel threads as opposed to aluminum. i am assuming the threads on the front of the heads for the alternator and power steering pump are helicoiled on the e-heads.

[Money Pit]

Goat4three, I work in the security fastener industry at McGard Inc, from wheel locks to water meter and man hole cover fasteners etc. In an application like this, it really is not necessary. There is no compromise in integrity. Kre d-ports are a superior head IMHO for this level.

[form406]

"spending money is one thing...but wasting it on components that don't work together is another."
follow your advice...
i dont think spending the $$ on aluminum heads and top end and not upgrading bottom end is a good idea...a hot top end with higher compression and and a bone stock bottom end could result in rod failure at high rpm...and a waste of $$$

[Goat4three]

alrighty then, where do i begin for a bottom end build up?

is summitt or jegs the way to go or do i want to start with KRE and JBP?

do i want forged or hypereutectic pistons (not planning on using nos)?

do i have to get the block bored (this may be a slight problem b/c i'm not too confident in the local shops familiarity with Pontiac)?

does a rotating assembly need to be "balanced and blue printed" for a 12 sec. street car?

if so, can this be done without having the assembly in the destination block?

can i use a stroker kit without needing any machine work?

thanks in advance to any and all who take (and have taken) the time to help.

[WARPed]

I would suggest that you read this thread before you make any decisions

KRE “d” vs. E heads

[Mr. P-Body]

There are others out there, too, with good offerings for Pontiacs. P-Dude is one. We use his pistons for the 4" stroke engines.
I agree, the KRE d-ports would be the better choice for a streeter. For a 406 CID (.030 over 400) engine, I would stick to the "285" version (advertised intake port flow in CFM). The 310s would be a tad much. The HSC chamber (High Swirl Combustion) makes tuning for pump gas a bit easier. Jeff Kauffman or Cliff Ruggles can explain it in detail.

Now, a couple of myths to bang on... "You can run a bit higher compression with aluminum". True enough, but that's not the whole story. You MUST run higher compression with aluminum to achieve the same power, all other factors being equal. The reason is that is aluminum "soaks" a lot of the heat out of the combustion process, making it less efficient. By increasing the compression, you get back some of that efficiency.

Edelbrock heads are only similar to the old factory Ram Air heads when it comes to intake and exhaust flanges. They are NOT "old technology". The intake port is fairly close, but if it ain't broke, DON'T FIX IT! The size (and therefore volume) of the port is really the significant difference between the stocker the E-head. The exhaust port is an entirely different matter. The "D" shape (not to be confused with Pontiac "d-port") has a round roof and flat floor. This is current port convention for high performance engines, regardless of family. With some judicious porting, the exhaust port can be made to "work" very well, despite the "droop nose".

All this is well and good, but if the bottom end is not upgraded to take the power the top end supplies, you're gonna have to replace it ALL again...
Edelbrock cams are generic in nature., That is, they are the same grinds all the other non-cam grinders are selling. Modern cam technology has past them by long ago. Comp and Crower are the leaders today. I understand Lunati is selling some of the old UltraDyne grinds, as is Bullit. For streeters, it's pretty hard to argue with the Comp XE series. If you can get a definitive "yes or no" from either Lunati or Bullit about the UD grinds, they would be among the better choices (provided it was "yes"). PIN THEM DOWN...
FWIW

Jim

[Goat4three]

so it seems that either head would be sufficient for my application (low to mid 12's on pump gas) as long as i match the intake and cam for the head choice.

as for the lower end, i checked out JBP's website and i was/am considering the 461-467 stroker rotating assembly. no substitute for cubic inches right?
i'm guessing that a .030" overbore and the stroker kit will get me to 461cid and .060" with the same stroker kit will get me to 467cid.

i've been told by some of my friends that i should probably get dished pistons to keep the compression ratio to 10:1 or less and then match the heads (combustion chamber size), cam etc. accordingly.

[WARPed]

Originally Posted by Goat4three

so it seems that either head would be sufficient for my application (low to mid 12's on pump gas) as long as i match the intake and cam for the head choice.

Yes

Originally Posted by Goat4three

as for the lower end, i checked out JBP's website and i was/am considering the 461-467 stroker rotating assembly. no substitute for cubic inches right?
i'm guessing that a .030" overbore and the stroker kit will get me to 461cid and .060" with the same stroker kit will get me to 467cid.

Yes

Originally Posted by Goat4three

i've been told by some of my friends that i should probably get dished pistons to keep the compression ratio to 10:1 or less and then match the heads (combustion chamber size), cam etc. accordingly.

I would go the other way, dish your piston(if needed) to match your chamber. And I would shoot for a cr of 10:1 for either Edelbrock or KRE "d" heads.

[Goat4three]

thanks.