does a T distrub have a #1 cyl. location? Of the 4 post, which is it?
You want to get your #1 piston at TDC on compression, and then see where that puts the rotor. Also, pay attention as to which way the rotor is rotating (this will determine how you wire the cap). Most likely your distributor cap will only go on 1 of 2 ways (due to where the spots to clip it are). You can put it on either way and that will change which post should be #1. Once you know where the rotor is, which way it rotates, set the cap down and whichever post it's on is now #1.
Remember, firing order is 1, 2, 4, 3. Having located #1 post, and with knowledge or rotor's direction of rotation, wire the other posts accordingly.
Any terminal on your distributor can be #1. There isn't a right or wrong one. Pick one.
Royce and Seth are both correct. You can make any terminal on your distributor #1 as long as you then rotate the distributor body so that the rotor is in the correct relationship to the terminal you selected when the #1 piston is at TDC on its compression stroke.
I did this on my 1971 Plymouth GTX so that I could rotate the distributor body to put the vacuum advance canister in a more convenient spot.
I'll describe what was called "static timing". On a modern you'd align the timing marks at what ever was called for with #1 cyl. on compression. On a T you'd get #1 just dropping off from TDC on compression. You need:
1: A test lamp
2: Dist cap off with points properly adjusted
3: Direction of rotation of the dist.with the eng running
Turn the ign. switch to batt.
Hook up the test lamp to the points.
Rotate the distributor in the direction it turns when running until the light just comes on.
If the lamp is already on don't turn it further in that direction.
Slowly turn the dist. against normal rotation until the lamp just goes out and lock it in place with the clamp.
Where ever the rotor sits is your #1 position and install the wires on the cap according to the 1-2-4-3 sequence. WE used to use this system when ever an engine had the distributor removed for whatever reason. It not only guaranteed a start because the timing was so close but occasionally it didn't even need further adjustment.