the "best" 400 ?
 

could it be said that the best 400 to find for a stock rebuild would be 70-72 ? this is after the 8 bolt pumps and rear pcv valley pans, after the long/short pumps and weird brackets and the heads are still "ok". the blocks are still stout. and the emmisions had not started choking them off. sure i know you can replace some of that stuff but if you were looking to use as much as the original stuff as possible ?

true ?

I like the way you think Steve! You're a master hair-splitter, like me.

To split it even further, any '67-78 block is good for a stock rebuild. You're really not pushing the envelope with a warmed-over 400, even the 557 castings.

The water pumps, brackets, emissions BS, etc is all bolt-on. So I'm not sure if you're talking about the best "bare block" or the best complete engine combination from the factory.

Best factory 400 engine combos would be 69-72 4bbl engine from F body or A body, because it would have high-comp heads, 11 bolt pump, later balancer, decent cam, popular exhaust manifolds, accy setups, decent Q-jet, etc.

Even then you can swap the timing cover/balancer assy from a '67-68 pretty easy, so any of the high-comp 400 engines are the best in my book.

BTW, have you actually put some time on that 557 stroker? How does it run?

Well like I said I know all that stuff can be swapped but why deal with that if you can just bide your time and find the one with the right goodies. Yes. I'm talking about the entire engine. The high comp heads may actually not be good tho because of crappy gas. This thought is about finding a 400 for a rebuild using all the original stuff and as low budget as possible. Might be better to have some larger cc heads so they could be cut a little for a bump in compression. 72 cc heads are not much good for a pump gas combo and low buck rebuild....harder to open them up for more cc.

Yes. I have put some time on the 557. It's a beast. I've revved it up to over 6k a few times with not much worry. The only thing keeping me from driving into the sunset with it and not looking back is my Muncie is giving me trouble. I've abused it with three different motors for 5 years with unknown origins and it's time for a freshen.

The only other issue I am having is the 77 block needs adapters to mount in my 67 chassis and it does not seem to fit right. Drivers side is a mess and I will likely have to pull it out because the header hits the motor mount, the frame, the steering rag joint, and is leaking at all exhaust ports on that side. The crazy thing is that my iron headed 421 used the same headers and did not rub at all. Still scratching my head over that one. Maybe it's a difference between the RAII heads and the eheads as far as the angle of the ports flanges go ? I may never know. Considering long branch manifiolds or dougs headers next.

i will vote for the 69-70 400 with the 62 or 13 heads. these actually cc out between 75 and 80 not the advertized 72. since it's a rebuild, i would guess you will be boring for new pistons. could get one with a little dish for peace of mind.

no. ideally no boring. just a hone ! now im launching into fantasy !!!

ok, then it's the 70 with 13's all the way. i base this on personal experiance. i've had two 70 Gp's with their original unrebuilt 400 and they ran great. plenty of power for a good fun factor. i did run them on 93 octane gas though. the 71 and 72 Gp's with 400's (also unrbuilt) ran good, but didn't have as much power as the 70, but you could run them on the cheapest junk fuel around.

i like to visit "fantasy land" myself, maybe i'll bump into there someday. ;^)

If your gonna be using cast pistons,you'll likely be screwed anyways,the only ones you can get anymore are those 8 valve relief POS pistons.

Unless your planning on re-using the OE cast pistons,but that's probably not the best idea either.

-OR- you find a set of NOS cast pistons somewhere...

IMO,on 400 builds,forged pistons are mandatory.

Just no other acceptable piston options.

Anyhow,enough of that for now.

As for blocks,I like the '70 to '74 blocks,as they have all the motor mount bosses drilled & tapped,so they fit any/all chassis easily.

Heads,lots of choices there.

Dont care for the '72 "letter" heads myself though,too many odd-balls in there,was a transition period,and they were doing some pretty odd $#!t around that time.

But to answer the question,if I had to pick one specific year/engine over all the rest,it would be the '71 300 hp 400 as my choice.

Big valve heads (#96),screw in studs,lower compression for use w/any pump fuels,has all the bolt bosses on the heads for any year brackets,has all the engine mount bosses to fit any chassis,has the 067 cam in that one,no EGR intake & old style choke for the Qjet,has the windage tray,has minimal emissions hardware,yadda,yadda,yadda.

Real easy to "beef it up" too if one wants to do so.

FWIW

Bret P.

Yeah. That's what I'm talking about. Is it possible that if you found one with low enough miles not to need a bore and just a hone the oem cast pistons will still be ok for a stocker rebuild ? There has to be plenty of old ponchos still around cruising around with those oem cast pistons in there.

My goal is to find the best 400 I can to rebuild on my own hopefully with no help from a machine shop. Tear it down, clean it up, buy a kit, drop it in, drive it around. Sure maybe not the best money spent but 100 percent done at home shade tree style. Like I said before.....I love the project more than the driving !! I have a nice stout 67 STD bore block to swap all my go fast goodies to from the 557 engine over to when I get ready to go back into that engine. That means no engine projects for a while. No acceptable. :) I have decided my balls have swelled large enough for me to attempt my first "solo" rebuild. I was considering doing a 350 to hopefully spend a little less but just can't bring myself to build such a tiny motor !;)

One things for sure, once the Q-jets started to come fitted with the early non- electric ATP you have more adjustment room to get the primarys set up of a bigger cam and or different CID motor with out having to change the metering rods and power piston spring.

I think if you use a 69 block and happen to use it's bracketry for alternator and power steering that you'll have to use the odd length 69 water pump.

Without "help" from a machine shop? So you have valve grinding equipment? Cam bearing tool? Hot tank? Crank polisher? One cannot do a "rebuild" without these operations being performed. Simply installing new parts without proper preparation is a recipe for disaster.

Even IF the bores are within "spec" (<.005" taper), re-ringing is "iffy" at best.

"Dishing" the pistons is the best way to reduce compression, making the small-chamber heads the best choice. We use the Speed Pro L2262F-xxx for this. Reasonably prced and tough stuff. Plenty of "meat" in the head for a dish.

FWIW

Jim

Technically, any 67-74 block would be fine, and even some of the 'select' blocks from 75-78. Those are supposed to have the higher nickle content, but that is splitting hairs.

I wouldn't worry about finding an engine with the heads you want, since that may push the budget higher (sellers of 'performance' engines may try to get more for people trying to restore). And since you have timing covers that aren't the oddball 69 ones, you don't have to worry about that either.

D-port/Round port is probably where you're finding the fit difference, as well as slightly due to the brackets. But, a 400 can breathe fairly well on nice manifolds, so you could always go that route with round heads. Ds you might as well use headers, since I believe you still have a set from the 421, correct?

I think you are dreaming if you are thinking cast pistons, especially OE ones. You're begging to blow it up that way, especially with a manual. Age/fatigue is your enemy. A bore isn't that expensive, and is good insurance for a number of reasons, bore clearances and ring seat/seal are some of the other biggies. It's not the fact that those parts would be a loss when they let go, it's the block. Those KB forged with a 14cc dish are only $350, not even sure you can get NOS cast for that. And it's what, maybe 20 bucks a hole to bore and hone? I think the last block I had tanked, bored, honed, and cam bearings/freeze plugs done for $280, just to give you an idea. (I have the reciepts, can verify). Oh, and oil gally plugs too. Think it was $350 to cut & polish a crank and balance the rotating assembly. $150 to square the decks, and $150 for align bore (mains). That's all from my head, but that's close I'm sure.

I'm tearing down that Olds this weekend and taking the parts up to the machine shop over the next week or so. When I go to assemble, maybe swing by, just to have some first hand knowledge maybe (and a few beers!). For the most part I can assemble the short block in a day, will have all the prep stuff taken care of beforehand.

.

aw man. dont rain on my parade. i guess i should have said MINIMAL machine shop help ;) no, i cant hot tank and magnaflux a block.....:rolleyes:

ok ok ok. i cant do it ALL myself and i cant use ALL the oem stuff. my lack of stating the obvious that will need to be done professionally is just evidence of my in-experience with building one from the ground up.

BUT i also think you guys are misunderstanding my goals. i am simply looking at doing this as a learning experience and fun on the side ! havent thousands of shadetree engines been built over the years in backyards the redneck way for decades ? remember i got my high dollar high horsepower motor. this is just for fun. and before anyone mentions money... YES it may be a waste of cash but right now i can afford to play a little. many guys spend a lot more on entertainment than what it would cost me to do this...i see it as entertainment.

the headers on there now that are not fitting were on RAII round port heads before and fit fine. now the same headers are on eheads and hit everything on the drivers side. the only things that changed were the heads (well the block too. it was a 66 421 block and now its a 77 400 block)

not trying to be argumentative but what is the difference between an old poncho tooling around at 200k miles and still running strong, versus a 60k mile motor being pulled apart and freshened up to go for another 60k with the exact same parts ?
im not getting it. this wouldnt be a performance build in any way just a tear down, clean, and zip back up.

maybe i should find a motor someone has already gone through and replaced some stuff in that i could do this to.

if i can i would LOVE to come down and watch the short block go together. ill even bring the beer !:)

I VOTE the 1971 400!!! Very strong main webbing and all the mounting holes you could use! Ummmm no I'm not partial or playing favorites or anything...;):rolleyes::jaw:

You must like tackling the impossible like a treasure hunter. The odds of finding a 67-71 400 with low enough mileage on it that: A. there isn't a deep ring groove B. the cylinders aren't egg shaped C. at a reasonable price is slim. It would have to be in a forgotten vehicle that was totalled early on or an engine pulled for "safe Keeping" way back. One of those ways you might get lucky the other less chance. JD

yeah i know. but i have been able to find lots of poncho motors around here, i looked at 4 complete ones in just the last few weeks. even bought one for the block. you never know what will turn up. why not keep the aim high ?

I should buy a lottery ticket then. I've found two early 400s (one complete runner, one a checked block) for $100 each. STD bore, never blown up. One of them is my current engine.

I started to do what you are describing about 2 years ago. I found a 72 2bolt main block with Edelbrock Performer intake in the 30 foot tall engine pile at the local car shredder. I got it put in the back of my truck for free since I have done work there. Started dissambly and found the 7K3 heads had been recently gone through with new springs, BBC studs tapped on the end exhaust ports and polylocks. The block was 30 over with 8 eyebrow cast pistons.:gag: N crank that has not been turned down but polished. Almost new double roller timing chain.
I bought a used set of domed 30 over pistons and was planning on a $1 per HP build. Then I found the bores need sleeving, but it is a thick main block.
So now the budget is $2 per HP.:D

aha ! i am not as crazy as i sound !

I have a 73 400 virgin Block & Crank std , cleaned ready to go.If anyone is interested.

northern canada ! :eek:

Only 1 more, and i'm DONE!...well maybe 2...
If gon'a build just "one" for street.

I vote out 67 blocks unless your gon'a use 67 hds, or bore out large enough to remove most of the cylinder chamfers for 68 and up heads. Maybe not that big a deal???
Other then that, any 68-74/78-79 "X" blocks.
"N" crank. Why didnt GM use'm the 78-79 "X" engines? Anyone???
King bearings(local spd whrhse stks them at good price).
60lb Melling select o/p and hardened shaft.
16, 62, 13, 96, 6X-4 hds.
12's and 48's i've seen where less then 72 cc. But if you want to enhance the cb while reducing cr. 670's are sweet for enhancing flow...
SRP pistons and "Ace's" forged rods.
Somewhere round a 744 cam spec cam or 230-240 range.
Highest ratio rkr arms and have cam ground from there by Bullit.
A GOOD link style chain. Still look'n for better one myself.
68-70 intake with 76-79 carb.
Long branch mans w/2.5" exh. 2.25 from muffs.
71-79 acessaries as lond as have matching setup.

BTY, i have a good extra 69 block with N crank been save'n jic.
May be able to talk me into sell'n.

You pretty much described my engine. :p Except for the block. :(

Stewart

Agreed only as crazy as chiphead! LOL I'm not buying the idea there are any "Stock/standard" bore 400's with a useable cylinder after 40 yrs. especially for $100. If you can find these blocks at "Welfare" prices you better buy as many as you can find because it will fund your retirement on the resale. JD

I recently had a bit of luck, I picked up a '72 455 motor complete which had supposedly been rebuilt before being stored under the bench, when I called to pick it up the guy gave me a pallet full of Pontiac bits including a 3" mains 455 N crank,a nos set of MT ali rods,TRW pistons ,mini starter,Mallory dizzy etc and loads of stock bits-timing covers,6x heads,400 block etc. When I inspected the 455 it has HS roller rockers,Moon timing cover,7H1 heads converted to big valves,TRW pistons etc,all old school Pontiac but still well worth the £500 ($750) I paid! The worst thing though was when he said that I could have also had the TEN Pontiac blocks that he had recently thrown in the dumpster 'cos he was fed up of tripping over them:(

Not nessesary a bad thing. Which one do you have?

see that ! another log on the fire ! dreams can come true.....

Mine's a '76 557 block, .030" over with SRS pistons and Ace's 4340 ultralite rods, re-balanced. The rest is in my signature. I can't see any problems with the 557 block at the rpm level I'm running with the seriously lighter-than-stock reciprocating assembly.

Stewart

I agree on your build MD. Shouldnt be a prob.
But what do i know. Only mess'n with them since i was about 10 yrs old...
DAM, just realized how long its been since the 1st time helped my father on his 57 Super Chief around 65.
And my older brother from 68-75.

That makes you close to 55 ? You got 15 on me and probably 35 more on me in Pontiac/car experience. I'm listening.....:)

Sounds like we are close to an age.

A story from an old boss: An incident happens in a city, a chase is underway. He hears the call and, off duty, responds. Pulls down on a car and they stop. "Why did you stop?", asks the officer. Response was, "Young guys are pussies, old guys will fcuking' kill you, that's why we stop".

Old guys rule. Never forget that an old guy is just too tired to mess with you and doesn't need the aggravation. You will die!

FWIW, Stewart