im getting new camshafts soon sk2s1 and was planning on installing springs..how important is it to install retainers as well??? what difference would it make if i dont??? the valves are bent and must be replaced also..i was looking at omni power..they sell the springs, retainers, and the valves for 540..is it worth it to get the combo and save 30 bux or just go with buying valves and springs and using stock retainers??