How many different casting numbers are there for aluminum BBC heads?

**Igosplut** · #1 05-22-2019, 06:05 PM

I once had an 842 head that was a later GM issue (late 70s, early 80s I believe). It had a different texture to the cast (much different), and I could never find a mate to it

**John Brown** · #2 05-22-2019, 07:41 PM

Have seen several of the 074 castings that had the better flowing 077 shaped exhaust ports. Must have been something that happened during changeover time.

L78racer · #3 05-23-2019, 12:02 AM

Quote:

Originally Posted by Igosplut

I once had an 842 head that was a later GM issue (late 70s, early 80s I believe). It had a different texture to the cast (much different), and I could never find a mate to it

I have a pair of those. Texture is different. Several other things different on them but the basic head is the same.

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