T5 mods

You should have no problems with a NWC behind the six, unless you've REALLY built it up anyway. Just a mild cam and 4V? I wouldn't speed shift it, but you should be fine with normal driving, even a bit aggressive...

The Chevy T-5 is commonly used for a lot of applications, like anything, if you go about abusing it the thing will break. There is no reason not to use one if you can get it on your engine. WC or not, it is up to the driver to keep it from breaking. The only reason the Ford was proved popular to use for the AMC engine is that it happened to be able to bolt on to an AMC V8 (or a late I-6) using a minimum number of parts.
To come down to it, the WC Ford T5 is weaker than a T-10 so technically there is no good reason to use it other than it fits easily.
I have had one installed on my 390 Javelin now for about 25 years and 50,000 miles and have not broken it yet, but I have made it a point not to break it. I also have one from a Merkur which used the Turbo 4 cylinder Ford T-Bird motor and transmission and enough parts to put it on an AMC engine. The Chevy transmission is easy to find and easy to get parts for and there is no reason not to install one if you can. You just have to decide what it is you want to do with it. If you want to beat it to death, contemplate building a 904 instead, a late 904 with a lock up torque converter and put in a 2200 rpm stall converter.

My stock never been apart AMC NWC T5 has been in there for about 15 years now.