4.2 to 4.0 swap

    Hopefully soon I’ll be putting a 4.0 in my 88 YJ. I have the engine harness for the 4.0 (it’s out of a 95) and I’m sure with some wiring diagrams and research I can figure out how to make the thing run
    My big hang up is gauges. I’d like to use the factory gauges. Has anyone on here done this? I’ve found some write ups online but nothing too detailed. There’s a really good one for doing this swap in a cj7 but I’m guessing the wiring part is gonna be a little different. I’m assuming I’ll need a dash harness out of a newer YJ?
    Any info in the right direction will be greatly appreciated. Just thinking about the wiring part of this whole swap stresses me out. Thanks

    i have done this swap many times. The gauges r indipedant of the computer. U may have to drill and tap the back of the head for the 88 temp sensor, oil sender u can just use the 88 one and ignore the 95 wires. If that bothers u, u can "t" the block port and run both senders. Spedo is a cable, u can get the pass through vss from a 91-93 for the t-case. The tach will work by tapping into the coil wire. I think its the gray wire.


    I have the diagrams if u get stuck u can come over and figure it out.

    correct. I did this swap in 1999 with a 91xj motor and harness and all my original 88 dash worked

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