My son wants more power and a bigger cam in his 71 340 Demon. Currently has an old hyd 268 Magnum cam (180 lbs crankng compression)and a Crosswind (Professional Products?) intake. 99% street car with 727 auto, 355 gears, Dougs headers, manual brakes, mopar performance dist, 770 street avenger holley and a mild stall wich power brakes to around 2400. I told him to install the LD340 intake we already have but he wants to put a single plane on it along with a Mopar hyd 508(?) cam/lifter kit while retaining the stock rockers and springs. I'm not sure this would be the hot set and would need new springs at least, so I am asking for your proven combos. Thanks Moparts members