No need to get lifters. The stock ones work perfectly when in good condition. With a 2500 stall and 3.23 gears in a light street car you can use up to about 224 @050 intake duration before you loose some low speed drivability. Stay under .525 lift with stock unmodified heads, more than that and you have to cut down the guides and change seals. Whatever you do, make sure to do the springs. Stock springs were barely adequate for the stock cam.