I agree with Double vision that a set of 416 305 heads might just be the ideal ticket for a 307 build.
That 307 has the same bore dia. as a 283. The 283 was built as a corvette engine back in the day, but they were never given heads with 1.94 valves. Not because GM didnt want better performance, and not because they didnt have better heads, but because of valve shrouding from the cylinder wall.
You definatly do NOT want to go 2.02 intakes. As I understand it, 1.94's will work, but there is so much shrouding that your overall flow would probably increase greatly with the smaller 305 intake valves. If it cant breathe, it aint gonna run..
Last edited by 65smallblock; 07-23-2010 at 12:20 PM.