the rules are pretty open... any 2bbl, any iron head, all roller OK... gas or alcohol OK. My questions are these... what factors should I consider in selecting cylinder heads for a 2bbl application? Does the 2bbl change recommendations for port sizing? The engine is a 4.030 bore x 3.875 stroke... 395 cu in., street stock car, camaro front, multi-leaf rear, 12" tires