need a timing light, hook it up to number one cylinder ... right front looking forward, take some chalk or white out and look for a line in the crank harmonic balancer, behind the lowest pulley, and use the white stuff and fill that line. there will be a metal tab over the pulley that in some way shape or form resembles an arrow.
Loosen the one bolt on the distributer. start the motore and turn the distributer clock wise or counter clockwise slowly ... very slowly while pointing the light at the indicator. when the line you marked earlier alligns with the indicatior over the pully ... your in time.
and one last thing before losing the dizzy, check it first to make sure it out, and there should be a timing degree on the radiator support indication the rpm ... check it and make sure your at that rpm when reading the timing ... good luck!
you pull it so you can set the initial timing, then when it's set, you plug it back in and the computer will compensate (advance/retard).
also, the timing is set for 10 degrees BTDC(before top dead center- TDC is the zero line.) Number one is passenger side front in case there was any confusion...
also, make sure the pick-up form the timing light (the big clip looking thingy) is facing the right direction. the arrow on it should be pointing in the direction towards the engine from distributor.