I assume you mean the sensor & the oil pump drive housing & have a 4.0. (?)
You don’t really need the DRB. It will be more precise with the DRB but by most accounts the computer will compensate for slight differences in the actual setting. It is only for injector timing, not spark. If the manual you refer to is the FSM then it has a very detailed procedure for installing it using a toothpick & finding TDC when installing it in a “rebuilt” engine (rather then pulling & reinstalling it back in the same engine where the crankshaft hasn’t been turned). If you are off too much you will get the CEL & either reset it or then take it to a shop with the DRB (some independent shops have them or of course the dealer). If you don’t get a light you should be OK. If you don’t have the FSM go here for an online read only manual & pick TJ Unlimited to get the ’03-’06 version. You need the Ignition Control section.
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