engine/trans swap

[rlcwagoneers]

I have an 87 gw w/360. The engine is close to rebuild or replace. I just found a 79 cherokee w/ excellent 360. I would like to switch entire drivetrains. I starting to transform the gw into double duty rig(off road/everday driver) and would like to lose all of the emissions and vacuum junk. what possible problems might i run into with such a switch?? I would like to retain the a/c. Also my 87 has a vacuum switch for 4wd, can this be modified, or should I install cherokee quadra??

[Marvin Gates]

I'll let someone else tell you what you are going to run into cause I don't think you want to know! Major undertaking. MG

[mdill]

Well, where do you start ? First what is wrong with the chero ? If you
like the interior of the GW swap it into the cherokee. I think the floor
pans changed in the 80 model year, so will the 79 stuff all fit under
the 87 pan without getting out the big hammer ? (body lift might solve
any worrys there) If the smog police ever come to your state your hosed
have to replace all the smog goodies. It would be a lot of work but I
don't see any real show stoppers. Other than time and money.

Mike D.

[Don S]

RL070400@AOL.COM... Welcome to IFSJa ... You might think about swapping bodies and gaining a 1" or 2" lift in the process. Good luck and keep us posted.. ds..

[porchpiggy]

I don't see any advantage/disadvantage betwen the drive lines. Why not just swap the engine. Also, I de-smogged an 88 GW, all that I have left for vac is vac ball, canister, vac advance, pcv, and power brake.(No smog check in KS) You are aware the front axle is different side drop? And if your ratios don't match you would have to change the back too. A lot of work for no advantage IMHO.

[derf]

Big changes between 74-79 and 80-91 SJ's:

1. Automatic transmissions changed from GM TH400 to Chrysler TF727. Linkages will need to be adapted.

2. Transfer cases changed completely from Dana 20/Borg Warner Quadratrac to New Process 2xx series.

3. Front axles changed from passenger offset to driver offset.

4. Rear axles on at least the Quadratrac equipped SJ's had offset differentials. I believe the D20 equipped SJs did too but don't quote me.

It may be easier to just swap the engine alone. The transmission bellhousings were specially designed to mate to the AMC V8 bolt pattern instead of the other way around so that part is a bolt in. The only thing you would have to do to the engine from the 79 is to swap the flywheel from the 87. Oh, and keep the starter from the 87 as well. Everything else should bolt right up, including your air conditioning. You might need to swap some pullies but that should be the extent of it.

[oldyellowwagoneer]

Originally posted by derf:
The only thing you would have to do to the engine from the 79 is to swap the flywheel from the 87.You'll also have to remove the very thin bushing in the back of the crank.
DENNIS

[Jerk]

Originally posted by scoutgrl:
</font><blockquote>quote:</font><hr />Originally posted by derf:
The only thing you would have to do to the engine from the 79 is to swap the flywheel from the 87.You'll also have to remove the very thin bushing in the back of the crank.
DENNIS</font>[/QUOTE]why do you need a pilot bushing in an auto trans? its only important for a stick tranny as far as I've been told, the flexplate bolts center the t/c and the bellhousing bolts take care of the rest. again, why?

[joe]

Originally posted by Matt W:
[QBwhy do you need a pilot bushing in an auto trans? its only important for a stick tranny as far as I've been told, why?[/QB]Why? who knows...but it doesn't change the fact that TH400 and all pre-80 360's/401's "DO" have a pilot bushing and the 80 ups don't and if you're installing a pre-80 motor into an 80 up rig w/ TF727/999 you MUST remove the bushing. "Why" it's in there in the first place is irrelevent...bottom line is you need to remove it.

[Jerk]

no, no... I mean why do you need to remove it? or install it, I've heard both, but understand neither, unless you are going into a manual tranny rig. does having it in the crank mean your t/c won't bolt up? mine did just fine and I put a factory 4bbl 360 from a 197? into a 1981.

[ibnfe]

You have to remove it to allow the centering lobe of the 727 torque converter to fit in the hole in the back of the crank. You could probably get away without having it for the 350 tranny, but the 727 lobe will not physically fit with the bushing installed. You will end up bending your flexplate or cracking your converter when you torque it down since the centering lobe isn't allowing the converter to sit properly.

[arter]

RLO,
Doing that switch now. Lotta work. If all you need is the engine then IMHO that is the way to go. Email if you want any sordid details. ;)