Help on rebuilding a 73 340

mopar rated the 72-3 340 at 8.5:1, cuz stock the pistons are down about .080" and chambers are about 69 cc. use the 340 heads and thermoquad and a modern, slightly hotter version of the 340 cam like a comp 20-309-4 - 222*/226* .464"/.464" 110* . and check crank - cast = external balance, forged = internal