yep they'll bolt on though some of the late 70's corvette and cammaro's have light 624 cast heads, like the 882's not worth messing with so check the numbers before ya pull em.

if ya pull the valve cover, the last three numbers are the slang term we use, "882" or watever ya call it. there is also a date code with a letter numericaly for the month, a number for the day and another number for the year, now its hard to tell if they are 60's 70's of 80's unless yer familiar with the cast #'s and marks.


drilling is as easy as laying the 400 head gaskets on, mark and drill the six holes.

lemme know what ya come up with, there is a chance ya have good ones though the 882 JJjuuuuunk is the most common.  

okay cool thanks mud, but where on the head should i look? ill get back to you on what heads they are when i get a chance to pull em off later this week  by the way what should my commpression psi be at for the stock 400?  

never mind on where took look for #s on head i pulled off my intake and vavle covers from the 400 just now and saw that yes the heads are 888s or 882s its kinda dark now so i can't really see too well, as you call them, im going to pull off the heads tommorow and try and see if the piston rings are any good, i did the wet commpression test and compression jumped from 75 to 100 psi but my dad still wants to look at cylinder walls so im pulling off heads to check, if motor needs new rings then im just going to put in the entire 350 from the corvette but if it just needs heads ill look for those good # heads you posted up mud, any specific cars they came in?  Also i don't have the money now to go with the flat top pistons so what heads do you reccomend that will raise my compression some without chaning pistons?  

all cylinders need to be within 10% of each other, a rule of thumb on the cylinder presure is 17-20 times the compression ratio... so ya should be closer to 140psi. the cam can also cause low cylinder presures.
75 is quite low, It's just wore out and tired. alot of engines start to get alot of blow-by when they get a new set of heads slapped on.

68-70cc heads will run ya near 10:1 compresion depending on the cc's of the stock pistons and the head gasket ya use.
041,441, 186, 034,
1969-1974 are the best ones to get a hold of.

487, 493, 993, 997, and 545's are about 74cc's

there is a down fall for the early heads,.... they need hard seats installed in em for today's gas. ya can wind up spending another 350+ for a grind, seats, guides and springs, I have the equiptment in my shop to do all that so I tend to forget about the cost for others sometimes.  

the gm vortec/fast burn heads can be had for around 300 a piece  (last time I checked) ready to bolt on. check with your local machineshop or dealer also jeg's and summit. the old style intake won't bolt on em and they use valve covers with the three center bolts...

http://www.gmpartsdepot.com/cylinder_head.html

theres just so many options and going beyond what stock was costs some bucks.

another thing to consider on the 400's is the short rods tend to hammer the piston skirts and taper the cylinders a bit, alot of em need a bore job to true em up, that also can affect the compression.

I generally always use stock 5.7" 350 rods and new pistons when rebuilding the 400's  

now that i took a closer look at the 400 heads the last 3 numbers i saw were actually 368 or 369 i cant make out the last number.. also will the bigger 74cc heads give me less compression arond 9 something wihci is waht im looking for? and where do i go to find those old heads do i acutally have to go look for them in old junk cars?  

hmm, you sure your engine is a 400?
369's are 76 heads.... that came on 90's gen.I 350ci goodwrench/targetmaster crate motors, If memory serves.. check the block # also, under the alternator on the head surface pad and behind the distrbutor on the bell mounting surface. It's still possible someone put em on the 400 though at some point.


yep the 74cc heads will give ya around 9:1 depending on the head gasket and the piston cc's

some machine shops have a healthy supply of em still on the shelves ready to go. and yes junk yards are still a good source along with the i-net from craigslist.org, e-bay, ect...  

okay i checked the heads on the corvette today and saw they are the crappy 882 heads you mentioned so i guess ill just get my 369 heads reconditioned or look for some 74cc heads to give a bit higher compression, im going have the machine shop pressure test it for any pin holes or leaks and im not sure wheater to have the vavles reconditioned or just by a new set of vavles? when u say the 369 heads are 76 heads you mean they are 76 cc and really 90s 350 ci crate motor? wow  is that a good thing?  also i dindn't see any steam holes in the head or the block so i don't think my motor is a 400 anymore , my glovebox tag said it was a 400, i have a rebuild book that shows where to drill the steam holes it looks like in between the two cylinders chambers and i see no holes in the head or block. i dindn't have a chance to look at block numbers where you mentioned but i have seen GM 8 on the back of the block by the flywheel/transmission hook up area if that helps any. thanks mud any suggestions on reconditiong heads?  

no steam holes in the block mean ya have the 90's gm goodwrench or targetmaster 350ci mexican built engine..(according to the heads)
it is a good base to work with, the heads will stand a mild port/gasket match also.

the 400ci would have had 6 steam holes on each side, two between each cylinder.

the vavles only need to be replaced if they are toasted/have sharp face edges. just have a basic grind/presure check/mag/ done. the stock springs are fine also.

do some reading and you can port match the intake and exhaust and clean up the runners, (don't mess with the chambers), yerself with a dremel type tool with stones or a carbide tip, do it before they go in for the grind.  

You know when I think back on this thread I think if it was me I would run 400 now until it died and I would be looking for a old 396/402 to put in its place. (I owned a few many many years ago) Those were serious motors and those "rats" responded well to builds and the stock exhaust ports on some of those motors was bigger than intakes on SB's and the intakes were huge. Those engines had what we used to call the old porcupine head. It was a big massive head designed with big valves in a staggered design for maximum flow potential. It was born as a true hi performance motor. Yes they are a bit bigger and weigh a bit more but a 396 can make some serious torque even at upper RPM's (more than a 400SB) and hold together too. While a 454 is nothing more than a bored and stroked 396, the 396 was a nice balance of bore/stroke ratio and rod length and wound up freer and safely higher than a 454 with stock parts.  

as it ended up it, the engine is a 350.
it originally had a 400.

I love the 396/402 and most of all the 427 also... goodluck finding one. they are plagued with crank problems.  

mudb8-.:
no steam holes in the block mean ya have the 90's gm goodwrench or targetmaster 350ci mexican built engine..(according to the heads)
it is a good base to work with, the heads will stand a mild port/gasket match also.

the 400ci would have had 6 steam holes on each side, two between each cylinder.

the vavles only need to be replaced if they are toasted/have sharp face edges. just have a basic grind/presure check/mag/ done. the stock springs are fine also.

do some reading and you can port match the intake and exhaust and clean up the runners, (don't mess with the chambers), yerself with a dremel type tool with stones or a carbide tip, do it before they go in for the grind.

yeah now that you metion it my heads did say made in mexico what ccs are they and do you have any idea what compression that moter came with, the pistions are almost flat with a small dish and valve reliefs  

mudb8-.:
as it ended up it, the engine is a 350.
it originally had a 400.

I love the 396/402 and most of all the 427 also... goodluck finding one. they are plagued with crank problems.

427's are lot harder to find than 396/402. I never had any crank issues and a treat one pretty rough too. Actually, a 427 tall block for a truck would likely not be too hard to find as they were used in MD and HD trucks for many years. The called them tall blocks because block was taller to allow use of longer rods for better geometry and better torque. They made a lot a 454 tall blocks too in MD and HD trucks. (C40 and bigger) Tall blocks take a different intake manifold though and would limit after market options.  

yep, yer right there on the tall block 427's..

I've got over a half dozen 396/402's in the shop with bad bottom ends and a few 454's, this is what keeps me into the small blocks...  

Now that you guys mention it, a 396 sounds like a real good motor, but how are the prices for aftermarket parts for it and how abundant are they, also how is a 400 a small block and a 396 a big block whats differentiates small blocks from big blocks??  

Night and day. A BB was born as a 396 to start with with massive heads and ports. It was de bored to a 366 for use in HD trucks and I rans one in mid 70's one summer in a C60 dump truck and ran the snot out of hauling and it never missed a beat and it was worn some when I drove it to. On a few runs my GCW was over 50,000 lbs (load and a float behind it with a back hoe on it)and it never failed to move it. I used to run a C70 with a 427 over 60,000 lbs on a wavier too.