a few questions about modding a cj6

i am about to aquire a 75 cj6 and had a few questions about mods/upgrades.
i have done some searching but have been unable to find the answers i was looking for.

1. are the 75 cj6 body parts compatible with the 76+ cj5/7/8? ie fenders, grill, hood, windshield frame
2. will the later model cj wide track axles bolt in to the 75 without modification? what about yj axles?
3. i would like to upgrade the springs to the yj style are there any kits out there to do so?
4. i would like to ditch the 3 spd manual and upgrade it with something that will bolt in. what auto or 5spd manuals will bolt in, if any? i have a dana 300 i can use to upgrade the tcase allready

 

Alot of this info can be found here using the search, but I'll post up some quick answers

1) body tub is not, The toher stuff can be adapted if necessary.
2) the spring perch width is different, your springs are narrower. Also, after 76 the rear spring are farther apart than on the earlier jeeps. The rear in you jeep should be the D44, which is superior to the later amc 20's found in jeeps. YJ axles will not bolt in for 2 reasons. the springs are wider, and the front differential is on the wrong side. Also, there is no strength advantage, actually the yj rear is one of the worst ever offered by jeep.
3) There are not alot of kits for anything on the intermediate jeeps. There are a few write-ups on how to do this swap though.
5) most autos are too long for the cj5, that why there was never one from the factory. Even 5speed are a bit legnthy when the adapters are added. A good option for you would be to find a later t-176 4 speed and use your d300 or find a t-18 4 speed and use your current d20.

 

thanks for the response. i have done some searching just havent gotten the answers i was looking for. however, i did just find the tech library tab so i will start looking there instead of the regular forum. spring perches arent a big deal, i have no problem cutting old ones off and moving them. i want wider axles for stability, thats why i was looking to the widetracks or yj. i know the d35 is a boat anchor but i wouldnt mind haveing the hp 30 front since it can be upgraded to 760 ujoints. i want to use the 300 because i can flip it if i decide to go with a driver drop front now or down the road. t176 is kind of hard to find around here another reason i was thinking of a 5spd. i didnt think the length would be an issue since it will be used in a cj 6.

 

The YJ Dana 30 would require a Dana 300 flip now. You should have a Dana 30 now( just passenger side drop) for a front axle just with drum brakes which can be changed to disks fairly easily. Also wouldn't a 75 have a Dana 44 rear axle?

With a CJ6 length the drivetrain is not as big of a deal.

 

Just to elaborate,
1) The exterior sheet metal of the later tub is basically the same, but the floors, dash, windshield and rear wheel houses are different.
4) This is a CJ-6, so just about anything will fit with some floor pan cutting. To get the best available manual transmissions and mate them to a D300, you'll need an adapter kit. There's no easy "bolt in" upgrade that's superior in strength to the three speeds. If you have a V8 with the T-15, that's a pretty good transmission ... The T-176 is an upgrade to the T-14 (that came with the 6s) IMO, but it has its own issues.

If you want an automatic, the CJ-7 from 1980 on used the TF999 with the Dana 300, and that would be a fine match to your CJ-6. The TF999 is Chryco's mid-line transmission, but it can be built to handle V8 power. Avoid the TH400 and Quadratrac transfer case that came in the '76-79 CJ-7 ... love or hate the Quadratrac, it's a can of worms and a maintenance headache. Another possibility is a TF727 from a '80 on Wagoneer, though you may need a two-piece front driveshaft to clear the pan. Not sure that the spline count matches the D300, but you could probably make it work.

 

Yes - nothing wrong with the rear axle except the width (if you really have to have wider axles).

Wagoneer axles are another option, but that requires some major fab work to outboard the front perches.

There's a wide Dana 44 rear that was used for the last year (?) of CJ-7 production. Like the AMC 20, you'd need to move the spring perches, and a knowledgeable seller would want a lot for one, if you could find one.

 

it has the 232 6 so i think the tf999 will be sufficient behind that. it does have a 44 but as you said the width is the main issue and i believe it has the 10 spline shafts??????? so i was told. a wide track 20 will suit my needs. i dont paln on running anything larger than a 33 and will add 1 piece alloy shafts.

i guess i should define my plans for this thing that way you will understand the direction i am going.
i want to build a cruiser/capable wheeler (mostly trails nothing extreme) on a budget. i plan on implementing the K.I.S.S method where ever possible. i want to have something capable of cruising at highway speeds comfortably while running 33s and 456 gears. i want to improve the ride and handling characteristics by going to yj width springs and keeping it spring under. i plan on using old man emu leafs and shocks.

 

sorry, i forgot it was a 6.


swap in a 350, auto and t-case out of a early 90's k1500! then you can use the hp 30 if you want.

 

i am considering that as well but figured it would be easier to swap in a widetrack 30 than go with wheel spacers and chnge over the brakes from disc to drum.

 

that would defeat the purpose of keeping it simple and if i wanted all that work and headache i would put a cummins 4bt in it since im partial to diesels

 

That should be a centered 30spline Dana 44 back there. Any reason to think it is a 10spline?

 

youre probably right, but thats what the previous owner thought it was.

 

You say K.I.S.S.
So, here is what you do.
Take it to a gas station.
Fill it up.
Wheel it.
With the longer wheelbase, the '6 will be more stable than a regular 5, and since you don't want to do any extreme trails, stock drivetrain will work great. Even with the lift and tires.
Don't get me wrong, I have nothing against people wanting to upgrade their Jeeps, but in and of themselves, a stock Jeep works better than most people can use it.

 

CAN Fnord5 get an AMEN.

Wheel it now as is. You got Dana 30 front and Dana 44 rear. I have a basic stock cj5, I wish I had your wheel base. But the stock setup is better then most think. Trust Me, Its really good. Stop reading sells adds. The wider axleS did not stop mine wife from rolling her YJ on a level dirt road. Dont Tell her I said this "ITS ALL THE DRIVER NOT THE JEEP"

The YJ dana 30 has a uni berring. Big pain in the @*% And the smaller bolt patten. 5 on 4.5.

 

Re the Wrangler springs, body roll will be mostly proportional to spring rate unless you move the springs more outboard. Is this what you consider handling? Certainly if you go with softer springs and increased ride height you will get much more body roll. The factory heavy-duty (10 or 11 leaf) springs handle well already - don't think you'll do better than that unless you fit sway bars. Most of these Jeeps handling problems seem to be related to worn parts.

If you want to modify, go to it, but I think I'd keep the stock axles for the time being and go ahead with the transmission swap. An automatic would be a fine upgrade, if that's what you prefer. The automatic was never offered in the CJ-6, but that was just because of the low production numbers and low demand. You can do this in stages - there's not that much advantage to doing all these changes at once ... and a running Jeep is much more valuable than a project. I'd do the transmission swap, then wheel it and evaluate what my next best change should be.

 

I was very concerned about body roll when I added the wrangler springs. I sourced sway bars for the front and rear as I was doing the swap. I did drive in in the alley without shocks in it and it was down right scary. After adding the shocks and driving it down the highway I decided against the sway bars. The ride is incredible. Easily the best SWB jeep that I have ever ridden in. Handling is impressive. I have a pic of my GPS driving down the highway.