hey i have a sbc 350 bored 40 over with vortec heads i want to run high compression but want to stay on pump gas i was wondering what type of piston i should use flat top dish or domed and what cr would i have with them thank you also if anyone know what cubic inch would my engine be bored 40 over thanks

 

a 350 bored 40 is 357. A flat-top piston with proper piston-to-head clearance puts you around 10.4:1, so you'd need a large cam, something like a 230 at .050" or larger. About a 12cc dish would be around 9.8:1, so something like a 218 at .050" or larger. Vortecs and domes are really really unwise.

 

thanks