Ok so I made a mistake by not marking the distributor before i pulled it i know stupid move. now I cant get it to start, any suggestions? 1969 stock 351W .
yes and no. yes you can when you are getting close to the number one cylinder at TDC compression stroke, but no you cant rely on the timing marks to determine the number one cylinder is actually near TDC compression stroke. remember that the crank turns two times for every turn of the camshaft/distributor, and if you rely only on the timing marks on the dampner, you may find yourself 180 out as the timing marks can also indicate that cylinder number six is at TDC compression stroke. pull the passenger side valve cover and rotate the engine until both valves on the number one cylinder are closed, then you can use the timing marks on the dampner to set the timing.
If you don't want to pull the valve cover (real pain on my motor) take out #1 plug. (front plug on passenger side). Use big wrench and crank bolt to turn motor over by hand, if you can. Have someone bump the starter (coil wire removed) if you can't turn by hand. Put your finger in/over the spark plug hole. You will obviously feel the compression when the cylinder starts up on the compression stroke. If your balancer is right, you should be able to move it slightly to get it to 0, TDC.
Now put in your dist. so the rotor ends up pointing at #1 plug position. Vacuum advance should be pointed about 5 o'clock (using 12 o'clock as top of dist towards engine). Rotor should be at 12, or slightly towards 1. Start your wiring, in order, counter clockwise, from the #1 plug location.