I got a 1990 RS with the 305 TBI. Im planning on upgrading my intake this weekend but don't want to start unless i know how to find TDC on cyl #1 which i need to do for re installation of my distributor. Can anyone help me out, thanks!

Line up the timing marks.

Also check that the rotor is pointing to the cap location for #1 spark plug (follow the plug wire). The timing marks can put you at TDC for #1 or #6.

If pointing at #6, turn the crank another full rotation. That will then be TDC #1.

RBob.

So when i line up the timing marks im looking for the rotor to be pointing at the # 1 piston or where the #1 plug wire would connect to the cap? Also, im new to working on motors so can you tell me where my timing marks are and which ones im trying to line up if there is more then two? Thanks for your help.

Towards the #1 terminal on the cap. The timing mark is on the balancer, line it up with the timing comb on the timing cover.

Roger that, thanks again. Is it the same way for re-installation?

One way to find TDC every time is with a piston stop.

Remove the spark plug from the #1 cylinder and insert a piston stop in it's place. Then, with a breaker bar on the crank pulley, rotate the engine carefully until you feel the piston hit the stop. Mark this position on the harmonic balancer. Then reverse the direction you are rotating the engine in and crank it until you feel the piston stop once more. Mark this position on the harmonic balancer. The location of TDC is exactly between those two marks.

It works every time.