1980 cj5 drive train?

[JeepMaster07]

Hey guys, I recently purchased my first project jeep. Been wanting for some time and finally did it..
Im sure to have alot of questions..hehe

First off... I was wonderning what the best drive train to run for a jeep..
I will have a 350 chevy with about 375 to 400hp.. I have a T-176 4 speed Transmission and not 100% sure of the Transfer Case .. I believe i have a AMC model 20 rear diff with a 3.07.. I believe this is correct..
What is a great combo to run with a 350.. Will the T-176 strong enough to hold up?
This is going to be a show quality jeep, not a mudd bogger.. A jeep to go cruise the town and what not..
Thanks for the help!!

 

[Sasquach]

400 HP to cruise town? sounds like a dragster to me.

 

[JeepMaster07]

Ha.. I have a nice chevy i have in the shop, a jeep is a good home for it... I also forgot to mention that I will run 35' tires on the jeep

 

[Kane]

Here is my take. The T-176 is a good strong aluminum tranny. It is not however as strong as the iron units that Jeep used in prior years. The T-176 can handle a mild stock small block 250-300hp without issues but the 400hp mark might be pushing it if you get the happy foot and start stuffing it all the time when Joe-mustang pulls up next to you at a light and you want to give him a run for his money. I had the T-176 behind my AMC 258 i6 / 4.2l inline but when i went to the small block pushing the same power as yours I got my hands on a T-18 out of a 79 CJ5 .

You Transfer Case is a Dana 300 which is plenty strong. The only week point is the aluminum tailshaft housing. If you found a T-18 it will most likely have a Dana 20 Transfer Case which is just as beefy and has a stronger tailshaft housing.

35 inch tires. You absolutely need one piece shafts on your model 20 rear. The 35s are pushing it for this axle but for strictly street duty, again keeping off the skinny pedal, they will be fine. I run 33's with this axle and I am not light on the right foot and they hold up well.

In my opinion since you own the motor and I know how expensive they are to build. Go ahead and use it but drop a smaller 500 cfm carb on it and keep the timing down to no more than 8 degrees BTDC and 36 degrees total mechanical advance and you should be fine. This will soften up your bottom end a bit and keep those parts together. But if you are like me, get the stronger Transmission because you will need it.

 

[JeepMaster07]

Thank you very much Kane for the information. I was wondering if the T-18 was a 4 speed also? I dont know a whole lot about transmissions.
What the best, like gear to run for highway driving.. I think it has a 3.07 Thanks again the info is very helpful

Btw..the Joe mustang example sounds like me haha

 

[Kane]

the T-18 is one of the strongest tranny that AMC used for the Jeep CJ and it is a four speed. They made two version for the CJ. One had a 6.32-1 granny low first gear and the more common unit had the 4.0-1 which is what i have.

You most likely have the 3.07 gearing which will be pretty high for 35 inch tires and your performance will suffer. i think 3.73 or 4.10 for 35 inch tires would be better. I run 3.55 for my 33's and it is perfect for street and mild offroading.

 

[JeepMaster07]

Looks like ima bite off more than i can chew..haha
I guess I can try to trade my Transmission and Transfer Case for a T-18 and Dana 20 ..
Thanks alot for the info.. Im sure to have alot more questions upcoming..

 

[Buuushman]

If you don't plan on wheeling this thing you may want to go with a T-150 Dana 20 setup, the T-18 's deep 1st gear is unsynchronized and pretty useless on the street, and the T- AMC 150 is a very strong tranny and can handle the H.P. you are throwing at it and also more readily available \ cheaper.

My 02.

Bush

 

[JeepMaster07]

This is what i was thinking.. so many options, tuff to find the right combo.. I want to be able to drive a 100 mile distance and not have the rpm turning 3500 so to speak.. That why i was sortof of looking into a 4 speed might help for a long trip... idk.. or with the granny low, it might not make any difference...

 

[Kane]

4 speed or 3 speed is irrelevent when it comes to highways rpms since they both are 1:1 ratio in the top gear. With 3.07 gears and 35's you will be seeing around 2500 rpm on the highway. With my Jeep I have 3.55 with 33's and I see about 2700-2800 at 65 mph. The T-150 three speed would be a good choice just for street duty and they are very cheep to come by with a Dana 20 attached. Plus the short drive line will be nicer for your rear driveshaft length.