400 Heads on a 350?

Working on a friends SBC motor. Here's my research:

Block casting # 3970010
Date code D248
Pad stamp suffix is CLR

Research shows it's a 1978 350 2 bolt.

Original heads had some cracks. He came up with some 400 SBC heads.

Casting # 3951598 76cc 1.94 IN/1.50 EX
Date code C11 & C3 70.

1970 400 heads.

I know that there are cooling passage differences in the 350's & 400's. So the ? is will these 400 heads work on the 350 block? And should I use 350 head gaskets?

Steve

as long as you arentputting non-400 heads on a 400 you will have no problem

only the 400 heads have the extra holes

others do not

no issue here

good luck

Correct - the steam holes present on the 400 heads are the only difference. Most 76cc head castings made in the 70s were used interchangeably on either 350 or 400 engines from the factory. If you do ever want to run 350 heads on a 400 however, you will need to have the steam holes drilled into it.

No big deal if steam holes are present on a 350- the head gasket will seal them.

Thanks you both..............Steve