Jeep Strokers

Hi,
I'm working on pulling a wiring harness from a 1991 4.0 HO XJ to use in a 1995 YJ. The motor is going to be a 94 4.0 block and head with the 258 crank and rods. I have the full wiring harness from the 95 YJ(which had a 4 banger). I'm trying to pull the harness from the 91 XJ. The harness goes into the firewall in a few places, and I can't get the full harness out intact. Should I just read the pinouts for the 91 computer, and trace each wire back? This seems like a lot of work, can anyone give me advice on this? I'd like to get the Xj stripped down and out of the way quickly, but don't want to just cut the harness at the firewall for fear of messing something up. Ideas?
Thanks

the harness went IN at the factory with the firewall intact. there was no engine trans or dash, but it went in, it has to come out the same way. as well, the main bulkhead will unblot from the inside half of the harness.

Were exactly are you getting snagged up? I just yanked my 88' engine harness out of mine and had it sitting on the garage floor. Now i was in the proccess of shortening most of the wires and and rerouting a lot of it to clean up the engine bay for my new engine but i don't remember anything that limited me from completely removing it.

do you still have the yj harness? im scraping all over the place looking for an engine harness...specifically the part of the harness that attaches to the back of the alternator

I've been told the only difference between a 4.0 and a 2.5 wiring harness is the 4.0 has 4 more wires for the 2 added injectors. If this is correct you should be able to add 4 more wires and switch to a 95 YJ 4.o computer.