Which way does rotor turn in the distributor?
My guess is that TDC would be the one with the most paint on it. Also you are going to want to be sure you are on NUMBER 1 COMPRESSION stroke. There are two ways to do that
1...Least popular, if you happen to have the rocker cover off say, to check valve adjustment, rotatee the engine to the TDC mark and look at the number one valves. If they are both closed, you are on compression. If they are both nearly equally open (split overlap) rotate the crank 1 turn
2....Second way is remove no1 plug. On a slant you cannot generally use your finger, so rig a compression gauge or other means (whistle) to tell when compression "comes". Rotate engine until you JUST start to get compression, the rotate until the marks come up. DO NOT set the wheel on TDC but rather WHERE IT IS that you want the initial timing to be, 5, 8 BTC, whatever. Then set the dist in GENTLY, and adjust the timing. NOTICE that there is a second adjustment under the dist. on a slant. One at the block, one under the dist. Two slotted holes
If you have points, rotate dist "retard" (CW) and gently rotate dist "advanced" (CCW) until points just break. If you have breakerless, adjust so the reluctor is in the middle of the pickup. This should be close enough to start.