f85 rocket

Back in the day, when real Olds raced in Nascar what heads were used on the engines ? I know they had specific blocks,but heads ? I can't see any factory sbo head flowing enough air for a Nascar mill.I don't think aftermarket heads could be used.

djchunter

Pretty sure they used gen1 batten's with a special batten SBO victor intake

f85 rocket

Thanks, for some reason I was under the impression that NASCAR had to run factory pieces.

hotrod1442

Batten heads have a GM part #22505805 (stage 3 head) not sure, but I believe they all used that # (stage 1, 2, & 3)

madmax442

They also used two different HP blocks! One was siamesed the other wasnt. Blocks came with 3.8 inch bores that were finished by race teams for their needed final displacement. Main sizes were 3.0, 2.75 and 2.5 inch. I have a 2.75 inch non siamesed block with 2.75 inch mains from AJ Foyt. From what I've read 2.75inch blocks were superspeedway engines while 2.5s were for higher winding short tracks.