1948 To20

i know this is dumb how do i know witch wire is #1 on the distributor cap

The one that goes to #1 plug.

A bit more clarification of you need would help get you a good answer. Did you pull all the wires off and are now trying to put them back?

Well not me but yes that is the situation all the wires are removed . I have two manuals I know the firing order just don't know where to begin on the distributor. Also one manual says to set the points 7 degrees before top dead center and one says 31 degrees?

If only the wires were disturbed, you just need to find Top Dead Center of #1 cylinder, remove the distributor cap and the rotor should be pointing at the contact for #1. then you put the wires in according to the firing order - in the direction the rotor turns.

Finding #1 firing:
1. Be sure the tractor is in neutral.
2. Crank the engine over with the distributor cap off. Note which way the fan (easy to see) and the distributor rotor turn for future reference.
3. When turning an engine by hand, turn the engine the same direction the starter turned it. If you have to "back it up"; turn it back more degrees than needed, then go forward again to get the gear train slack removed in the proper direction.
4. With # 1 spark plug out, bump the engine over while holding your finger over the plug hole to tell when that cylinder is coming up on its compression stroke. Stop before it reaches the top. (The engine will turn easier if you take all the plugs out. A remote starter button will allow you to crank/bump the engine, without the switch on, while you are at the engine doing this.)
5. If possible, use a rod or wire through the # 1 spark plug hole to touch the top of the piston. If it is a "L" flathead the cylinder may be off to one side of the spark plug hole.
6. Manually rotate the engine by hand while monitoring the movement of the probe. When it stops rising TDC has been reached on the compression stroke. (If it is a straight line to the piston through the plug hole a long travel dial indicator can be used to monitor the piston, similar to how some small engines are timed.)
7. Check to see where the rotor button points. It should point at the # 1 plug wire contact position in the distributor cap.
8. The points should be open or just closing. This shows the timing is close.
9. Look for a mark on the flywheel or dampener pulley for this position.
10. The plug wires, in the proper firing order, should follow the direction of the rotor travel around the cap.

You need to know that the cylinder numbering is 1-4 from the radiator back. The firing order is 1-3-4-2. Find the Compression stroke on #1 by pulling all the plugs(makes cranking easier and eliminates the possibility of starting), holding your thumb on the #1 plug hole and bumping the starter to until you feel pressure on your thumb. #1 is now on the compression stroke. Loo in the window at the timing mark and crank the engine until you have it at 6 BTDC, the timing point. Take off the distributor cap and see where the rotor is pointing. It should be pointing at the cap terminal that the #1 plug wire emanates from. This is generally around the 10 o"clock position. Since the distributor turns CCW, the # 3 wire should be in the next hole in the CCW direction, then the #4 and then the # 2. If you need to time it then come back and I"ll explain that also.