340 with big hopes

AAAAHHHHHHHHHH, Thats the $64,000 question, it varies from builder to builder and head porter to head porter, some like radiuses and some don't. I always build engines for the need and the mods are done for the need. Per the parts used. It's a matter of preference from the builder or the engine owner. Wide seats run cooler and narrow seats run hotter, wide seats don't make as much HP as narrow seats. IMO I would follow the NHRA rule book for stock and super stock valve jobs and you'll be fine. They give it to you in some detail.



BJR Racing