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mousemjh12 05-22-2013 09:22 AM

In the process of doing an engine swap in an 90' YJ. I'm running 44" Super Swampers with 4.56 gears as of right now. I had an inline 6 but have purchased an AMC 401 to put in its place. I currently have the AX15 transmission and NP 231 transfer case but have the plan of replacing with a T19 transmission and Dana20 transfer case. What are all of the issues that I will run into and how do I go about fixing them?

Randonexplosion 05-22-2013 09:29 AM

The first thing that I can think of is your Dana 20 t case will be passenger side drop.

mousemjh12 05-22-2013 09:40 AM


Originally Posted by Randonexplosion
The first thing that I can think of is your Dana 20 t case will be passenger side drop.

Yep, discussed that last night. Is there an easy fix? Do they make an adaptor? Or would it be unwise to cross it over?

mousemjh12 05-22-2013 09:42 AM

Forgot to mention that I'm running a Dana 44 up front and a Dana 60 in the rear.

Randonexplosion 05-22-2013 09:47 AM

I dont know much about flipping transfer cases but I know it can be done. Check out Novak or Advance Adapters for the drivetrain adapters

instg8tor 05-22-2013 11:55 AM

wouldn't it be easier to get a chevy 44 or 60 front and not worry about flipping the xcase?

Randonexplosion 05-22-2013 12:01 PM


Originally Posted by instg8tor (Post 15466555)
wouldn't it be easier to get a chevy 44 or 60 front and not worry about flipping the xcase?

I would think so. Or try to adapt the trans to a 241 to keep it driver drop.

mousemjh12 05-23-2013 04:42 AM

That was another option. I found a Chevy Dana front 44 with Ford lockouts and a Chevy 14 bolt rear end with matching 4.10 gears, so that might be might best bet I'm guessing at this point

mousemjh12 05-23-2013 11:41 AM

If I were to go with Chevy axels, what gear ratio would be best suited for my set up?

YJ4LIFE 05-23-2013 02:09 PM

why not run the ax-15?

mousemjh12 05-23-2013 02:35 PM

I could, I'm not against it, just came across the T19 and Dana 20 for dirt cheap and they were in great condition, I'm still learning but I've had a few people tell me that the AX15 is hard to beat, just not heavy duty

ratmonkey 05-23-2013 04:54 PM

not the best motor in the world, it can be built, but it's expensive to make any decent power from. a fuel injected 4.0 makes similar numbers stock vs stock.
for 44's i'd be looking for minimum 5.38 gearing, probably even higher with bigger axles. i really can't believe you're able to go anywhere that isn't pavement with 44's on a d44/60 combo too. that's a lot of tire.

Chrisnvegas 05-23-2013 06:00 PM

44" super swampers. For mud? If so, a built automatic. Period.

mike_breaker_5 05-23-2013 06:22 PM

there is nothing about an ax-15 np231 combo in front of 44"s that is going to last very long. especially after tossing in v-8 power. the ax-15 will give up the ghost first, i speak from experience.

44"s is alot of tire like rat said, there is no way on gods earth i would think anything numerically lower than 5:13's would even come close to keeping you in the power band for the older 401 amc motor.

i am merely going on speculation since i have no concrete evidence other than common sense to go on. it is pretty much a standard to go with 4:88's on 37"s, this is the only piece of data that i am basing my statement on.

i'm not even going to touch the axle debate, god kills a kitten every time someone argues axle/tire pairing on JF.

remmons 05-24-2013 11:04 AM

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If your front D44 is a right hand drop, then you should have no problems with that set up. I would have to agree that the stock 401 v8 vs. injected 4.0 both produce nearly the same numbers, and both can make great motors if you're willing to invest in them.

But, my old hot-rod motto is "there's no replacement for displacement."

The time now is 03:56 PM.

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