340 build help

Disassemble, check tolerances, if fine, hone the cylinders, polish the crank, add some new rod, main, cam bearings, and rings. (I would @ least check rod bearings for wear if nothing else) Have heads checked out. Chances are the exhaust valves are sunk into the head a little causing the exhaust tips to set higher than the intake valve tips (can check with straight edge with rockers off). If so a valve job and get the tips evened out. Cam her up (voodoo LUN-10200703LK 226/234 .494/513). Holley 750, good intake, some headers and rock and roll. I would recommend a higher capacity oil pan (i like my Kevko a lot) Don't run a high volume oil pump with a stock pan....