optimus2

it seems i can get my hands on a 81 j20 for what sounds like a reasonable price. and seeing as how my xj is getting a fresh start with a new chasis it seems this migh tbe a good time to think about the futur and what drivline i wont to end up woth. the d44/d60 axles seem like a good idea and a lgical way to go but i am unsure of it the 4 speed manual and the transfercase mounted to it would be a good way to go. also it would be coming with a 304 v8 and im not sure if that would be giving me a step up or down compared to the 4.0l i have now. i have not done much research into this yet but figures this would be a good place to start getting advice.

end result i would like to run on 35 with lockers and have it basicaly bullet proof. my wheeling generaly stays pretty mild, but i can have a bit of a heavy foot. when i can afford it i would like to work in enough power to turn the tires i put on it no matter what i can get into, so im trying to keep that in mind. as far as futur engine is concerner nothing is set in stone but i am considering a stroker 4.6l or something comparable.

any thoughts?

Lowrange2

My bone stock 4.0 has more than enough power to spin my 35's.

Cramming a carbed 304 in a Cherokee would certainly be a step down, IMO.

optimus2

i have heard that before, and that is why i dont plan on going after more power till some time down the road. what about the rest of it. the trans and transfer case that that truck would have come with, would it hold up better or stick with the set that are in the cherokee. i am told eith way will mount to the 4.0l so i can go either way. keeping mine is easier but i dont want to have problems if they wont take it .

Lowrange2

You'll be fine wiht the stock drive train.

I wasn't aware that a 304 and 4.0 had the same bell housing bolt pattern...

ktmracer419

the 44 is a decent swap, about the same as the waggy and j10 44's that people swap in. except this is 8 lug, has better brakes, and a beefier housing. Its significantly heavier too iirc. I wouldnt install it without upgraded shafts and u joints however.

The 60 I wanna say is a 30 spline full floater. Again, not a bad axle, I wouldnt put it under my cherokee unless you bore the spindles and run 35 spline shafts.

Keep in mind the gear ratio is probably useless with 35's in an xj too.

as for the rest of the drivetrain. Keep what you have now. the aw4 and 231 are fine with 35's and they are already there. If you have a 5 speed and want lower gears for crawling look into a 231/231 doubler. or even a 231/dana300 doubler.

optimus2

i dont know for sure they have the same bolt patern(4.0l to 304). just something i was told. but a pretty reliable source. not sure what gears i would need stock engine to be able to preform with the 35s need to be able to start on hills and launch in a short stretch. still learning /looking into this stuff but trying to get it right the first time.

ktmracer419

4.88 minimum, 5.38 maximum.

optimus2

so for the amount it would cost to rebuild with the upgraded parts is this something that would be suggested ? again 35s and mild running . mostly trail/mud or should i be looking for an 8.8 and not deal with the extra. still trying to figure out what i really need dont want to be doing this twice so to speak. so i dont mind going bigger now to save me latter but if im getting into stuff that i will never be close to needing maybe it is not worth as much money/trouble

5-90

Gen-II/III V8, late 6-232, 1975(ish)-up 6-258, and all 6-242 use the same bellhousing pattern.

However, the AMC pattern isn't directly compatible with anything else (popular are the Chevvy V8 - all later GM V8 except BOP, later GM I6); Dodge LA-block (V6-238, LA V8, LA V10); or Ford (Windsor et al)

Adapter plates are available for some of these, however, check with Novak. Also, the whole drivetrain may be swapped in - it's common to throw in an S10 V6-3.1 or 3.4 w/THM700R4/4L60 and NP231C for 1984-1986 XJ w/V6-2.8L w/"Baby 904" & NP231J (this gets you a better engine, gains an overdrive range, nets a stronger transmission, and a transfer case with a wider drive chain.)

Some adapting, obviously, is required.

I'd like to throw an AMC V8 engine into an XJ just for fun value (I've seen SBChevvy, BBChevvy, and Ford Windsor thrown in - but an AMC would be more appropriate, and is a stronger engine - mechanically.)

Or, since the BBChevvy can be put in with little to no sheetmetal work, perhaps do the redesign to throw in a Gen-II 426ci Chrysler Hemi?

You are primarily limited by tools, time, and money. Nearly anything can be done, if you're willing to put in the work. (I almost bought a 1972 Datsun pickup that had a 1988 Corvette drivetrain put in - fan to rear axle. It had a shortened driveshaft and the fenders had QD latches to remove them for a tuneup, but it was all cleanly done. Looked stock...)

xjmarc

At a minimum you'd need to swap your t-case to run the 44 front since it's a passenger side drop. This will envolve cutting your floor and doing some sheet metal work and redoing your exhaust to clear the front drive shaft. J-truck axles aren't technically full width but are wider than stock XJs at roughly 63" wms to wms.

optimus2

got lucky i guess with the truck i found was stock with a diver side drop. so no added fab work there, and i could continue to run my stock t-case. not sure what year they switched from the passengerside to the driver side drop but i hear it bounced around a bit.

xjmarc

If it's driver drop it's not an 81 or someone swapped the axle.

optimus2

Thats handy to know. Will have to find out what part if the info i have is not right. Year or it beign stock. Stated clear that it was a driver side drop in the add, but i have not seen the truck myself yet

ktmracer419

The stock front axle under an 81 fullsize jeep (j10,j20,waggy,etc) is drivers drop.

Stop putting out false information.

xjmarc

Guess mine was an oddball then because I wheeled an 81 J20 with a passenger side drop D44 up front and it was the stock axle.