Do you have a notch in the crank pulley?
Do you have a timing light? Some have a knob that allow you to dial in the 5� BTDC
There were at least three timing gear covers. One with T and 5� grooves, one with a slight hump/bump and one with no marks.
You can find a close TDC by removing the #1 spark plug, (the engine is easier to turn if you remove all the spark plugs) placing your finger tightly over the #1 plug hole, and turning the engine until you feel the pressure of the compression stroke. This pressure will change to vacuum as you continue to turn the engine. TDC is near where that pressure changes to vacuum.
You then might be able to see the top of the piston in the bore, looking through the plug hole.
There is an add-on timing indicator but it needs a little tweak as it's for the M-38 with a larger pulley..
https://www.ebay.com/itm/Jeep-M38-M38A1-Timing-Indicator-NOS-G-740-G-758-/173130861535I bought one and modified it...I had the un-marked timing cover..
http://www.cj3apage.com/cgi-bin/3Ayabb26/YaBB.pl?num=1372878148Once you find TDC your rotor should be near the position shown in the picture...