I'm about to buy a cheap rebuilt engine from Autozone for a 71 Corvette and one of the things they ask about for the core is what head casting number you have, 049, 781 or 292. Since I'm not interested in getting the core charge back, which one of these would be the best heads to get? Is there any difference? This is going to be used in a street car which will be mostly stock except for headers and a performer intake. I want some nice oval port heads to get low end torque so I assume any one of these will do, anyone have any info for me?