I'm not sure on a Jeep, but most late model vehicles have "distributorless" ignitions, utilizing a fixed pickup on the crankshaft for "base" timing information and adjusting the timing according to current engine and driving conditions and the instructions programmed into the engine computer. If all you see under the hood is a coil pak (multiple coils) wired directly to the spark plugs, you have this system. You need to have the computer "reprogrammed" or buy a power chip. Talk to a performance shop or look in the back of any number of cas/truck enthusiast magazines for sources.
Blacksmith