Has anyone ever ran a T-84 three-speed behind a V8?

I have a Ford "copy" of a Borg-Warner T-84 and Spicer 18 from a GPW. I'm going to put it into my M38 which has a stock 2BBL 350 from the early '70's swapped in it. I know that the T-84 isn't known for strength, but the only reason I'm going to use it is because it's already setup for a T-90, and I can't afford a 4 or 5-speed conversion.

So, will it hold up to the three-and-a-half?

Thanks, TheJeeper.  
Get a real jeep! (pre '75)

I would not expect it to last long. You would be better off saving your money for an adapter and new tranny so you don't have to make driveline modifications twice.

Besides, as far as I know of, there are no adapters for the T-84. It is different than a T-90. And the Spicer 18 in your Jeep will be marginal. It likely has a 3/4-inch intermediate shaft. See if you can find a later Spicer 18 t-case with a 1 1/8 or 1 1/4 inch shaft. This will hold up much better to the V-8 power.  

I am eventually going to swap in a SM465, or NV4500. Albeit it'll take a long time to gather the parts for the swap considering my budget. I just want to get the Jeep going quickly by running the T-84.

What exactly are the differences between the T-84 and T-90? They both appear the same.

And, I have 3 or 4 extra Spicer 18's lying around, so I have my options.  
Get a real jeep! (pre '75)

The T-84 is a totally different tranny. It is not the same as a T-90. They both have the same bellhousing bolt pattern but that's about it. A T-90 has a case length of 8 inches, the T-84 is much smaller at 6.75 inches.

But the real issue is Advance Adapters says they have adapters for the T-90, and then goes on to say they don't have any for the T-84 and don't recommend using it.  

Pmed ya about sm465 to dana 18 adapter, along with jeep t-18 to gm bell adapter  

I'm aware of the case-size differences, but the bell-housing bolt pattern is the same, as well as the input-shaft length.

I'm just planning on using it to get me by until I can get my 5-speed setup. So, it'd work, right?  
Get a real jeep! (pre '75)

Man, I don't know how to be nice about this. You clearly are not getting it. No! The T-84 will not bolt up to the Chevy V-8 no matter how badly you want it to. This is because of several reasons. One of which is that using a T-90 behind the V-8 requires that the T-90 get a new input shaft from a six-cylinder version of the tranny. There is no six-cylinder version of the T-84 and the factory T-84 input shaft will not work with a V-8 swap. It's the wrong length and wrong spline count. There is not an input shaft for the T-84 that will work with a V-8. A six-cylinder T-90 shaft will not fit. The T-84 will not bolt up to a Chevy V-8. Repeat after me... THE T-84 WILL NOT BOLT UP TO A CHEVY V-8!

Get it now?  

The T-90 that currently resided in the Jeep when I got it, was a short (7in. stick-out length, from a 134ci.) input. It has a very, very narrow bell-housing. The input shaft from the T-84 is exactly identical to the T-90 that was removed from the Jeep, both sharing the same spline-count, and length. I even slid the clutch onto it to make sure they were the same, and it fit exactly as it did the T-90.

I've come to find out that no one has ever heard of using the 4-cylinder version of the T-90 behind a V8. And I haven't the slightest idea what transmission was behind this bell, but it appears as the factory bell from the 350, as it has the same paint. I'm guessing maybe it's from a GM car three-speed? I don't know. But it, coupled with an adapter, a homemade extra long bearing retainer, and a 10-spline clutch will work with a 4-cylinder T-90.  
Get a real jeep! (pre '75)

So why don't you just use the T-90 since it's a better tranny than the T-84 anyway?  

Because it's a POS. First and second wouldn't pull at all. And I don't have the money to rebuild it.  
Get a real jeep! (pre '75)