OEM cylinder head castings - 1977 K10

[bucket]

What makes you say 1972? Those were used on Goodwrench crate engines, too. Thank you for checking, btw!

Because they don't say "Hecho en Mexico" on them like the Goodwrench engines did. Iirc, the older Target master engines were made in Mexico too, but not positive on that.

 

[83 Box]

I was alive and kicking when the 882s were in use. While OK, they tended to crack and the heat riser went int two of the exhaust ports (one on each side). There were a lot better open chamber heads that would make decent power and could put up with some performance abuse. I still have a short (5.565") rod 400 sbc that made a bunch of power for it's day. It's sitting in my storage unit.
One of the most important things about getting the most out of open chamber heads is getting the squish right.

The link below may be of help in your search.

Good luck.


SBC cylinder heads

 

[Intenseblue]

I was alive and kicking when the 882s were in use. While OK, they tended to crack and the heat riser went int two of the exhaust ports (one on each side). There were a lot better open chamber heads that would make decent power and could put up with some performance abuse. I still have a short (5.565") rod 400 sbc that made a bunch of power for it's day. It's sitting in my storage unit.
One of the most important things about getting the most out of open chamber heads is getting the squish right.

The link below may be of help in your search.

Good luck.


SBC cylinder heads

I've got a pretty good grip on what's available and what is good and what isn't. I know whatever came on these is going to be sh*t and know that they came with 1.72" intake valves.

This is just a fun sleeper experiment for me. I expect a bone stock looking AND sounding engine that will produce over 250 horse and 350 torque. I plan on maximizing machine work almost exclusively on stock parts.

I've already got some rebuilt by me hand ported Vortecs if I decide to change my mind. I just want to play with the original stuff.

 

[Intenseblue]

The two castings that are pulling up that seem to be possible are 882 and 624. I don't know if they were getting both for different packages, which I can't see why they would, or if maybe they were getting different castings depending on the plant assembling them.

I do know that according to 77 literature that the trucks under 6000gvwr were getting 1.94 intake valve heads, and the ones over, which would be every K-series truck were getting 1.72" intake valves and no catalytic converters.

Also there is a difference it seems in the original 929 cam in early years in advertised duration and LSA even though the .050" numbers are reported the same and the part number didn't change.

 

[idahovette]

If you are doing a lot of "hidden" work, what difference does it make if you don't have original heads.......nobody is gonna see the numbers with the valve covers on???

 

[Intenseblue]

If you are doing a lot of "hidden" work, what difference does it make if you don't have original heads.......nobody is gonna see the numbers with the valve covers on???

Ive never messed with the smog-era heads, but the castings usually have giveaways on the front face of the heads as to what they are, such as the double/camel humps. They're known as that due to outside casting markers, not the internal ones. The other part of it is OCD (I guess).

 

[vr1967]

Remember that GM went to thinner (lighter) castings in 1977, so if you get 882 castings, there is a difference in early and late heads. The early heads had a straight edge under the spark plugs, where the later heads were “scalloped” around the plugs.

Early heads

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Later heads

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The 010 blocks also got the change. Easiest way to tell the later (lighter) castings is they had the narrow pad on front, instead of the wide pad.

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(Pictures grabbed from the net)

 

[Intenseblue]

Remember that GM went to thinner (lighter) castings in 1977, so if you get 882 castings, there is a difference in early and late heads. The early heads had a straight edge under the spark plugs, where the later heads were “scalloped” around the plugs.

Early heads

You must be registered for see images attach

Later heads

You must be registered for see images attach

The 010 blocks also got the change. Easiest way to tell the later (lighter) castings is they had the narrow pad on front, instead of the wide pad.

You must be registered for see images attach

(Pictures grabbed from the net)

GM started the lightweight castings in late 74. I did not know how to spot the differences from an external view. Blocks, either. Thanks a bunch for the pictures!

 

[vr1967]

GM started the lightweight castings in late 74. I did not know how to spot the differences from an external view. Blocks, either. Thanks a bunch for the pictures!

Here is a 1975 cast thick block. Can see the wide pad and cast dates in photos 7 & 8

Core Short Block Engine 8-350 5.7L 2-Bolt Main Fits 1975 MONTE CARLO 1170018 | eBay

MONTE CARLO 75-77 8-350. ANYTHING LISTED AS A CORE WILL NOT HAVE A FULL WARRANTY. INTERNAL PARTS OF A CORE ARE NOT COVERED UNDER THE WARRANTY. Not covered under warranty: An engine block is found to be rebuildable but the internal parts are not in working order is NOT covered under the warranty.

www.ebay.com

Here is some Dec 1975 cast heads that are thick castings. 2nd photo shows date and flange. Plus I cropped and rotated the second photo for better viewing.

1970-1976 Chevrolet 350 v8 engine motor cylinder head 3998991 #1 | eBay

1970-1976 Chevrolet 350 v8 engine motor cylinder head 3998991 #1.

www.ebay.com