Your engine should be a hydraulic roller camshaft, factory GM style lifters. These lifters limit your lift to about .605-.610. The factory cam is 224/224 duration @ .050 on a 115 Lobe Separation Angle, i forget the lift. The largest cam I would select for a 502 is 230/236 duration @ .050 and put the LSA on a 114. Get a custom grind with as close to .600 lift as possible. Keep in mind you will need to change the non-adjustable rocker arms to a roller adjustable style of rocker arm to handle the lift. What computer does your engine have, the MEFI 1 or MEFI 3. The 1 is a rectangle shape about 3X 7 and the MEFI 3 is a square about 4X4. Either can be made to work, the MEFI 1 has less IAC control. The computer will need to be re-calibrated and I would cut the dividers out of the lower intake manifold air passages. I recommend you call Bob Madiera @ Marine Kinetics and talk with him 585-654-8583, he is very helpful with camshaft selection and can provide the product. Good Luck.