Jeep 1989 258 into 1979 CJ7 w/ Quadratrac? -
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Unread 12-16-2002, 09:42 AM   #1
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Jeep 1989 258 into 1979 CJ7 w/ Quadratrac?

I've got a '79 CJ7 with a 258 & Quadratrac. The engine's getting pretty tired. I can get a 258 from an '89 that can get rebuilt. My concerns are if the engine mounts are in the same place, and if the TH400 trans will bolt-up to the newer engine.

Would this be a drop-in swap, or am I looking for trouble? I'm not concerned about the wiring, because I'm running an aftermarket ignition system.

Thanks a bunch!

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Unread 12-16-2002, 01:25 PM   #2
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i have a 258 out of an 81 or 82(not really sure) AMC eagle in my 79 with QT. it was a complete drop in. CJs have the th400 with the amc bolt pattern so it should bolt right up. i am unsure bout the mounts. i may be completely wrong but i believe they changed mounts in 87 but i think that was only cause of the wrangler frame. the mounting points on the block should(?) be the same. so when you pull your engine, pull the mounts offa it. is the engine coming from a 4wd? remember to pull the pilot bushing. when swapping a 300 ford from a 4wd truck to an automatic van, i spent hours trying to figure out why they wouldnt mate up. i dont know if 258s are the same though. good luck.
[COLOR=darkgreen]"character is doing the right thing even if nobody is looking"[/COLOR]
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Unread 12-16-2002, 01:57 PM   #3
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Yes the block is identical. Like Rusty said the biggest thing to remember is to remove the pilot bushing from the back of the '87's crankshaft. Use the flexplate from the '79. It it were me I would also use the '79's fuel and ignition system. The '87 will have the POS computer controlled carburetor and emissions systems which can be a real headache.
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Unread 12-16-2002, 02:00 PM   #4
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Thanks for the input fellas- I think it's gonna work
-Tony P.
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