Well I took my heads to the machine shop to have them torn down, cleaned and a valve job. The dude there told me my heads were 400's. What does that mean for me? I'm a 350 retard so any info would be great!

And when I get parts for it (ie push rods, etc) does 350 stuff work on the 400 heads?

The only major difference between the 350's and 400's is the 400's have steam holes in them. They match up with holes in the 400 block. Putting them on a 350 will not harm anything. The head gasket covers them. The remainder of the hardware is interchangeable.

:beer:

Originally posted by rodzzilla
The only major difference between the 350's and 400's is the 400's have steam holes in them. They match up with holes in the 400 block. Putting them on a 350 will not harm anything. The head gasket covers them. The remainder of the hardware is interchangeable.

:beer:

SAWEET!!!!

Will I get any performance increase out of them? Dude said they have "big" valves (2.0x) and that's about all he said :D

And I assume by what you said a 350 headgasket will work on the 400 heads.

Thanks man!

400's are usually smog heads. I would bet they are 882 castings which are not bad, but there are better. The larger valves are a good sign they have been gone through before, IIRC

Originally posted by zakk
400's are usually smog heads. I would bet they are 882 castings which are not bad, but there are better. The larger valves are a good sign they have been gone through before, IIRC

I should be able to get the casting # and look them up then. Is the 882 one stamped with that # on it?

Originally posted by brector


I should be able to get the casting # and look them up then. Is the 882 one stamped with that # on it?

yes. it will have some number XXX882 or sumthing like that. Use the last 3 numbers to get a "casting number"

Have you looked into the Vortec heads? those are supposed to be the best factory heads ever to come out of GM's stable (for a SBC)

If you can deal with a bit more $$$ they outperform anything in that price range, especailly for waht we do.

Originally posted by zakk


yes. it will have some number XXX882 or sumthing like that. Use the last 3 numbers to get a "casting number"

Have you looked into the Vortec heads? those are supposed to be the best factory heads ever to come out of GM's stable (for a SBC)

If you can deal with a bit more $$$ they outperform anything in that price range, especailly for waht we do.

If I had the $$$ I would. But I've already got the complete motor - so I'm just trying to get it going as cheap as possible. Thanks!

Originally posted by zakk
ah, i see. Are they bolted up already? has the guy finished rebuilding them?? A simple gasket match can gain 10-20hp and much better throttle response.

They are at the machine shop right now. I was thinking of a bowl blend and gasket match - but I was thinking I might be able to gasket match them myself w/ a die grinder. Can I do it myself?

Originally posted by wedge
I have a '78 350 with '72 400 heads in my '87 k5 an rv cam, 600 Edelbrock, MSD ignition, Torker II intake, Headers, dual flowmasters.

I can melt my 33's till the cows come home. lots O power!

The 400 heads I have are cast thicker around the valves and such so they won't crack as easily as a 350 head. I don't know if this applies to all castings though. No idea on valve size or chamber cc's either, otherwise they work fine. Cheapest mod I did too, traded two 10x15 chevy mags for 'em.

I am putting on it: edelbrock performer intake, quadrajet, probably a boat or rv cam, new roller timing chain set, new push rods, and maybe some new stamped steel rocker arms.

Originally posted by FroadALicious
no

NO what? If you are replying to his question of match porting, I have to disagree.

Match porting to the gasket is a piece of cake. Just take your gasket, attach it to the head (I usually use a couple of bolts with washers just to keep it snug), and mark it with a scribe or a sharp sharpie. Then use a grinder to open the port to the scribe marks. Don't go crazy in the port though. Just grind enough to smooth the edge to the gasket. Now do the same on the intake. I have found when grinding aluminum, spraying it with WD40 every couple of seconds helps a lot.

Keep in mind that all you are trying to accomplish here is smoothing the airflow where the intake and heads meet. Again, don't mess with the actual port runners unless you know what you are doing. Leave that to the pros!

Originally posted by erich_in_AZ


NO what? If you are replying to his question of match porting, I have to disagree.

Match porting to the gasket is a piece of cake. Just take your gasket, attach it to the head (I usually use a couple of bolts with washers just to keep it snug), and mark it with a scribe or a sharp sharpie. Then use a grinder to open the port to the scribe marks. Don't go crazy in the port though. Just grind enough to smooth the edge to the gasket. Now do the same on the intake. I have found when grinding aluminum, spraying it with WD40 every couple of seconds helps a lot.

Keep in mind that all you are trying to accomplish here is smoothing the airflow where the intake and heads meet. Again, don't mess with the actual port runners unless you know what you are doing. Leave that to the pros!

Thanks! That's what I thought :D I gasket matched my toy head myself and it was aluminum.

Originally posted by brector


I am putting on it: edelbrock performer intake, quadrajet, probably a boat or rv cam, new roller timing chain set, new push rods, and maybe some new stamped steel rocker arms.

If you can afford it get some good roller rockers, you'll gain around 15hp. The stamped steel ones are no good they break in half at higher RPM's especially with heavier springs or a higher lift cam.

Originally posted by wedge


If you can afford it get some good roller rockers, you'll gain around 15hp. The stamped steel ones are no good they break in half at higher RPM's especially with heavier springs or a higher lift cam.

I was wanting to use a roller cam w/ roller lifters and add roller rockers later. But I am strapped for cash right now. So I should just re-use my stock steel ones and not get new stamped ones?

Originally posted by brector


I was wanting to use a roller cam w/ roller lifters and add roller rockers later. But I am strapped for cash right now. So I should just re-use my stock steel ones and not get new stamped ones?

I could be wrong on this, but I think if you are going to run a roller cam, you will need different rockers. At the very least I would think you would need "long slot" stamped ones. With a roller cam, I would save my $$ and get roller rockers.

just my $.02

Originally posted by erich_in_AZ


I could be wrong on this, but I think if you are going to run a roller cam, you will need different rockers. At the very least I would think you would need "long slot" stamped ones. With a roller cam, I would save my $$ and get roller rockers.

just my $.02

I forgot to say - I'm going to run a regular cam (rv or boat) and stock type rockers for now. I was just wondering if I should keep my stock ones or get some stamped ones since they are fairly cheap ~$50.

if you are buying them now, upgrade to roller rockers, ecery company makes them.

roller rockers= less friction and less friction = more HP

Originally posted by zakk
if you are buying them now, upgrade to roller rockers, ecery company makes them.

roller rockers= less friction and less friction = more HP

What sucks is stamped rockers are $50, steel roller tipped are $100 and full on rollers are $150 for aluminum. That $50 to $100 buys my tchain kit or cam.

Originally posted by brector


What sucks is stamped rockers are $50, steel roller tipped are $100 and full on rollers are $150 for aluminum. That $50 to $100 buys my tchain kit or cam.

Welcome to HP country.....LOL You figure out how many times you wanna "be into" you motor......I usually only choose once. Who says HP is cheap........The cheapest way is NOS and I run that too.....ROFLMAO......Start rolling quarters/dimes/nickles/pennys brian.....lol:p :p :beer: :D

Originally posted by Shaker


Welcome to HP country.....LOL You figure out how many times you wanna "be into" you motor......I usually only choose once. Who says HP is cheap........The cheapest way is NOS and I run that too.....ROFLMAO......Start rolling quarters/dimes/nickles/pennys brian.....lol:p :p :beer: :D

Damn - more stuff to spend $$$ on :flipoff2:

HP country! I've been there! it's as green as far as the eye can see, couldn't afford to stay long though!

If it's all you can afford definitly go new with the stamped rockers.

Oh, very important, break-in your new cam EXACTLY how the instructions that come with it recommend!