according to AutoZone at
http://www1.autozone.com/shopping/specsSelect.htm
it is:
"Ignition Timing
For your 1975 Jeep CJ5 (5.0L 2BL OHV):
5 Degrees
Note:
Before top dead center
*Set at warm idle speed (750 RPM)
*Distributor vacuum hose disconnected & plugged
*Transmission in neutral (parking brake engaged)"
Automatic or manual?