Trying to find some replacement heads for a friend. He says he has a 76 350 and he thinks the head bolts are different size than earlier SB's...can anyone confirm or deny?
Thanks
Tom

 

The head bolts changed in 77 from 7/16" to 1/2" All SBOs 76 and earlier were 7/16"

 

Hey Tom
I know the 403 used a larger head bolt, but I don't know about the same vintage 350's. My first question would be does his engine have the older style head, possibly a number 8, or one of the newer heads with a large A after the number? If it's the #8 I think its likely the same sized bolts as the 1968-mid 1970's heads. If its the newer style head someone who's more familiar with this vintage will have to speak up.


John

captjim, you beat me to the punch! Thanks for clarifying it for us.

 

Yup. 1/2" vs 7/16, te cutoff date was somewhere around '76 or '77.

The locating pins should be the same though, so I think you could install them.

The thing is, I've never heard of anyone doing that, because everyone wants to do the opposite: Replace crappy low-compression #8 heads with earlier, better #5, 6, or 7 heads.

- Eric

edit: you guys are fast

 

I have both solutions here for you.

I have a good running pair of 76 #8 heads here, and if the headbolts don't fit , it's easy to drill cast iron out for the bigger ones.

 

To clarify, the head bolt size was changed from 7/16 to 1/2 when the blocks went from solid main web to windowed main web. This happened in the 1977 model year. All 1964-1976 Olds motors use 7/16" head bolts. All 1977-1990 Olds motors (including diesels) use 1/2" head bolts.

 

Thanks all for the lesson! It turns out he is going to order a rebuilt set of heads from Advance.....I wouldn't. But I'll let you know how that all turns out.