Transmission and transfercase

I recently picked up a 72 Cj that is pretty much from the ground up project. I'm starting with the engine, it is a AMC 360 that I am building up to be a monster more less. So I am wondering if there are any suggestions for a beefy tranny and transfer case to put behind it? Or any other suggested heavy duty equipment so when I put my lead foot down I am not blowing everything up? Any Help would be appreciated.
-Jason

 

HMMMM ... good stuff ! .... the stock stuff I have for my 72 360 ,,, handles it petty well , If you can find a T-18 four speed ! Thats the best for grannny gear crawling.! After that its alot of work and mods. The easy for bullet proof whould be the Atles Transfer case to get real low crawl ratio. But.... what i said 1st My stock drivetrain handles the 360 just fine ,,,, and i race those new mustangs street light to streetlight . And I pull out trees for the people next door. I like to always remember............. the jeps are pretty good on or off road just the way they came... anythang else is just gravey!!!!

But you can't go wrong with a 360 with this set-up !

 

What size tires are you planning on and what is the intended use?
BorgWarner T-18 truck 4 speed is a great upgrade and can be done with factory parts as well as from the aftermarket. Driveline mods will be needed and you will need to pay attention to rear driveshaft angles. You should have model 20 transfer case which is plenty strong for most people but has kind of a lousy low range at 2.03-1. Since you are upgrading the transmission anyway a Model 300 transfer case would be a great upgrade if you can find one available. They are a little stronger and have a great 2.62-1 low range. They have a different bolt pattern and require a different adapter which is the reason for the comment above. Down side is they are very popular and only used from '80-'86 in CJ's only so they can be hard to find in decent shape. There is a version used in '80 IH Scout 2's that has the same bolt pattern as your 20 but as you can imagine they are very scarce. An Atlas or STAK transfer case would be the ultimate for strength but start about $2000. 300's can be had for anywhere between $300 up to about $650 for rebuilt units and there is a ton of aftermarket parts for them.
There are low range conversions that can be done to the 20 to give either a 2.46-1 low range or a 3.15-1 low range. The gear set for the 3.15 goes for around $650-700 though so can be expensive. The 2.46-1 conversion can be done using factory parts but requires a hard to find gear from an early Bronco transfer case. Do a search for low range conversion as we've covered that extensively if interested in more info. More info on intended use will help us give you a little better info and more options....

 

Now send pics of your jeep !!! PICs are always welcomed !!!! lets see that jeep eye candy !

 

Nicmil, I'm from the North West so this is going to be a trail rider and a mud slinger if all goes accordingly. I'm hoping to run 37s on it but that really us going to depend on the lift as I am finding they aren't really easy to come by for something this old. But anything else you got I'd be happy to listen.

Desert Storm, Thanks for the input and the pictures will be coming. Righ now all you would have to look at is refnished tub sitting next to a chassy with wheels and a freshly hot tanked block on the other side. Hopefully I'll get some progress pictures here soon.

 

No send those pics ,,,,, the beginnning photos are always great !!! Or save em up for a whole build thread here !!! Jeeps are still pretty even when there a rusty hulk !!!!!

 

Alright I'll see what I can do once I go get the rest of it out storage. Now the t-18 isn't the same as the ford t-18 is it?

 

It just has a longer input shaft,,, a few mods and it will fit ... But its the same.

http://www.jeeptech.com/convtrans/fordt18/

Look at this !

 

What sort of transfercase do you run? For me it isn't a matter of upgrading its a matter of getting one, since I don't have that or a tranny.

 

T15 and dana 20 ,,, All stock !!!! remember these jeeps are bult for the off-road and other years upgrade to what we have in the 72-75 AMC years !

 

The T-15 is a good trans for a 3 speed, but it's still a 3 speed and doesn't have a granny low first gear. Parts are getting harder to find for them too. Have 3 cores at the shop all with stripped main drive gears and cluster gears.

If starting from scratch I'd go with the Ford T-18 and adapt the back to fit whichever transfer case you decide to go with. It will bolt right up to your AMC motor with a '76 up CJ bellhousing that had an AMC motor. The T-150/176 bellhousing will bolt right up and is the right depth. The SR-4, T-4, and t-5 bellhousing must be drilled and tapped for the transmission but the bosses are cast in already so no problem there. The Ford T-18 wide ratio has a 6.32-1 first gear which is great for trail running. If the money was available I'd go with the Ford T-18 adapted to a Dana 300 transfer case for the gearing and strength. If not then go with the T-18 adapted to a 20 transfer case. you can always upgrade the gears later if you so choose. The advantage to the 20 is they are more readily available and the adapter is only 1" thick so the rear driveline angle is better. If you don't find what you need locally contact R&P at 503-557-8911. They stock rebuilt T-18's, 20 transfer cases, and 300 cases as available. They can help with the low range conversions as well. Check their prices, apples to apples they are frequently cheaper than a lot of shops in your area and they guarantee their work....

On that vintage of Jeep 37's are a bit large. I'd stick to around a 35" tire which is plenty for an 84" wheel base vehicle. You want to consider axle strength and frame strength as well and anything over 35" is a bit much in that department for that vehicle. That being said, it's your vehicle and you can do whatever you want with it....