SR4 replacement options for 1980 CJ

mechetti

New member
I have a 1980 CJ7 that has been completely rebuilt with a 360V8, Dana 300, 3.73 gears, with the exception of the stock SR4 from the original 6 cylinder. Last week, it exploded on me. I need to upgrade the transmission now to handle the rest of the truck. I did a little research and it looks like there are no bolt in upgrades available, so I will need to modify drivelines, bellhousings, and purchase adaptors. I drive the Jeep on the street mostly, so do not need a transmission with a compound low. I would like something that shifts easy, but can handle the power of a V8 with about 300HP. Is a T-176 is my best option if I go with a manual? Has anyone ever converted to a TH400, and if so, is it difficult?

Jared

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I believe that a T-4 (4 speed) Or a T-5 (5 speed) Will bolt right in with no modifications. With 300 HP you might want to do the TH400 swap. I've never done that swap but it will be easier on the rest of your drivetrain.
 
The 6cyl bolt pattern is the same from the 6 up to the 401. Your limiting factor is the 300tcase, Most of the trans from the 70,s can handle your v8 but never came with the 300. The trans from the 80,s will bolt to the 300 but may not be able to handle the power of your engine. Your bellhousing shouldnt need any mods, but you will probably be buying an adaptor for something, either bolting a trans to the motor or the case to the trans. As far as going to the automatic, I think you will be in the same boat. Automatics of that era had quadra trac transfercase and never came with the dana 300, so you will need adaptors going that route as well. If money is a issue for you, DARE I SAY THIS, you could ditch the 300 and go to a dana 20. That would allow you to put in a trans that will handle the v8 and not need a adapter for the 300. By the way, your jeep looks real nice. read you post again and I think the t176 is your best bet. It should bolt right to the 360 and will except the 300 bolt pattern, you should look more into this. I think it will work,but does have a lower first gear.
 
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The 6cyl bolt pattern is the same from the 6 up to the 401. Your limiting factor is the 300tcase, Most of the trans from the 70,s can handle your v8 but never came with the 300. The trans from the 80,s will bolt to the 300 but may not be able to handle the power of your engine. Your bellhousing shouldnt need any mods, but you will probably be buying an adaptor for something, either bolting a trans to the motor or the case to the trans. As far as going to the automatic, I think you will be in the same boat. Automatics of that era had quadra trac transfercase and never came with the dana 300, so you will need adaptors going that route as well. If money is a issue for you, DARE I SAY THIS, you could ditch the 300 and go to a dana 20. That would allow you to put in a trans that will handle the v8 and not need a adapter for the 20. By the way, your jeep looks real nice. read you post again and I think the t176 is your best bet. It should bolt right to the 360 and will except the 300 bolt pattern, you should look more into this. I think it will work,but does have a lower first gear.

I made a miss type on the dana 20tcase, just wanted to fix it.
 
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Thanks for all the info. I have been leaning towards a T-176 as I don't need a compound low and it sounds like it will bolt up fairly easily without too much modification. Considering buying a cheap SR4 just to get it running while I find all the parts for the T-176 conversion.
 
the T-176 will bolt right up to 360 and dana 300 will bolt right up to the T-176 had that combo in my 80 cj-5
 

Yep, I got the 304/t176/ dana 300 combo. I wouldn't change it for nothing.
 
Now if I could just find a T-176. Been looking for almost two months locally. I may have to start thinking about shipping, but I really want to see what I am buying!!
 
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