I've torn apart two L98's, both happen to be from a 89 350TPI had flat tops with 4v reliefs in them. So its not always true.

The iron headed L98 has 64cc chambers, and the aluminum headed (read 86+ Vette) had 58cc chambers.

 

Thats the thing about GM, you can never say never. I allways wonder if they just use what they have setting on their shelves at the end of a run instead of keeping things completely constant....lol

 

Arao makes those 4 V heads

 

Yeah, but I only have the 4v reliefs, my heads are just standard 2v sbc heads from a L98.

I've seen the claims for those 4V heads and they are impressive. I don't know if its just tire smoke, or actual truthful data.