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Old 02-06-2014, 12:10 AM   #1
rutgers1700's Avatar
Join Date: Mar 2013
Posts: 3
304 in 87 yj

Ok so I need some help here guys. I've got a 87 YJ with a 304v8 from a 78cj. The moron that did the swap used the original wire harness to the 87 which leaves about 10 unused wires in the bay. I'm running a msd 6a system. It's a true hack job and I'm redoing everything. Should I use the harness there and cut back what I don't use or should I get a new harness? If a new harness then should I get one for a 78 or 87 and how do those commingle?

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Old 02-06-2014, 08:12 AM   #2

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Location: south georgia
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easiest thing to do is to just clean up what you have

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Old 02-07-2014, 06:02 PM   #3
Join Date: Sep 2013
Posts: 51
Agreed, clean up what you have. I was in a similar position with my YJ. Stock 258 but the wiring was a mess. The only wires you should need on that harness are the distro/ignition wires that are horizontal on the firewall, the vertical wires on the drivers side and the headlight wiring the gos down the drivers side fender. Google the stock 87 wiring harness, start with the wires that dont go to anything and delete them making sure first that your not going to need them. The wiring on my YJ was too thin of gauge for the ignition and the fool used duct tape to wrap his connections so source out anything like that and correct it. If your fooling with wiring its not a bad time to consider ground upgrades.
This is everything I pulled out of my wrangler:

Good luck.
1987 Jeep YJ 4.2l I6 - 33x12.5r15 BFG MT KM1, 3.5" Black Diamond Springs, 2" shackle lift,Nutter bypass, Vacuum delete, JB Conversions SS SYE, Magnaflow 40,
BUILT NOT BOUGHT X Flexy and I Know It!
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