If you are planning on adjusting your timing make sure you check your harmonic balancer berfore u do anything. If it looks worn and has rubber sticking out replace it. I didnt check mine and wound up setting the base timing and with a timing light i "set it to 12 adv." but since my balancer was shot which i noticed a month and a half later with detonation and never being able to get it back where it was i replaced the balancer and seen my timing was at 28* advanced. Replaced balancer reset timing to 12* and now its perfect. Im lucky my motor didnt blow from all the detonation/ping. Be careful. Dont make the same mistake i did. One more thing. If you buy the proffessional products balancer from 5.0 rest u will have to find or buy new bolts for the pulley. The stock ones are too short by a long shot.