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Google "www.Magnumswap.com". A guy who had a stock short block 5.9 , with minor bolt ons run 11.70's @ 116-7 here. Named "LX guy " here. Have one in my 72 Scamp, runs nice. Best daily driver 5.9 here, would probably be " Trailbeast" aka Greg. I highly recommend the E.Q. replacement heads over stock Magnums( better air flow, available in LA intake manifold bolt pattern). The flexplate will need to be offset ground, on one hole. The 5.9 comes with a serp setup balancer as a one piece, Professional Products, makes a harmonic balancer to replace it.97 on up comes with a weighted flexplate, knock the weights off a 360 or cast 340 torque converter.Long tube headers should be mocked up , on the engine stand. (Some times the truck engine mount bosses need to be ground down to clear) Use a 360 LA oil pan to fit. Otherwise, straight forward swap, for a LA small block.
Thanks" I've used EQ heads on some Chevy builds I've done. Just cut em for 2" and 1.65 Ferra LS valves. Made nice fast burn heads.