Originally Posted by backroadin'
I'm assuming you mean beacuse of where to mount the clutch master cyl.? Might look at wrangler pedal setups and see if the clutch pedal could be made to work with the fsj bracketry under the dash. Also, you could get a smaller aftermarket booster like the hotrod guys run so there'd be room to mount the clutch master.
The lenght specs will let you know if you need to alter driveshafts and where your crossmember needs to be. The ax15 looks to be a good deal longer than your 4spd, so I'm gonna say plan on driveshaft mods and probably not having the stock crossmember match up to the existing frame holes. You could always fab up a crossmember to work with the existing holes in your frame, or just drill new holes. Also, will the t18 bellhousing bolt to the ax15, or does it need to have a different one? If so, you'll have to factor in any difference in length of the BH, plus extra length of tranny, plus length (thickness) of adapter plate to get your overall length diffrence.
The ax15 has the shifter coming out the rear, while your current tranny has it out the top, so the shifter will now set back some - as will the tcase shifter due to the added length of the tranny. There were two diffrent lenght linkage rods for the fsj tcases - the shorter ones for v8's I believe, so maybe some i-6 linkage might keep your tcase shifter in the same floor hole.
Honestly, you can do a ton of pre-planning with just a tape measure, as alot of your mods will be due to the extra length. When you're under there, you'll notice what needs to move and where.
As long as the rig isn't your daily driver, I say jump in and go for it, and let it take as long as needed. You'll run into snags no matter what usually, and it'll be esasier to get advice/info on specific problems vs the whole swap. My jeep was originally a 3spd, and it's now a close ratio 4spd, and so much more enjoyable to drive. Since it'll make the driving experience better for you too, I say that's reason enough.
I'm running a t176 from a cj. They made a t177 for the fsj's too. They don't have granny gears. It doesn't have the overdrive you'd like, but it is manual clutch and easier to swap as far as lenght considerations go. Driveshafts are still probably needed, but shifter placement, crossmember placement, clutch linkage, etc. is much simpler. As long as you're not flogging the pee out of it with a hopped up motor, either of those trannies will hold up just fine behind your 360. Just another option...
Thanks for the great feedback and encouragement Backroadin! I do have quite a bit of experience, I've restored about 16 old mopars, and had a few FSJs, but ALL were automatics (except my first car, a 73 Challenger, which I sold bc I burnt out the clutch). I recently had to pull a A833 from a van so I could replace the freeze plugs, so I got a little experience with Manuals and feel like this shouldn't be too big a deal, but thought that there would be a wealth of experience with this swap bc it seems so ideal.
I still need to find the right trans, but it looks like I can get a new one from Novak and all the rest to stab it in and make it work, then re-length the driveshafts. I have a lot of homework to do on this, but it sounds pretty doable.
I hope this has the same impact swapping the 727 for an A-518 made in my 70 Challenger. Its a better upgrade then the 2008 Hemi I put in it.
Modern Trans and Seats - Yes, late model EFI engine - No... Its just not that worth the trouble/cost. You can get all the benefit with just a bolt on TBI system. IMHO.