It will work, just don't drop the clutch, pull anything or plan on drag racing with it. I now a guy that put one in 84 chevy stepside pickup. Took it to the 1/8 mile drag strip on the first weekend that he installed. He had a mild 350 and just wanted to see what kind of numbers that he could come up with and to see if could get better numbers than the TH350 he had in it.
Well about 3rd gear the transmission just spilled its guts on the track. Totally destroyed the tranny. This tranny came out of a V-8 305 Camaro with 60k on the clock, they also put the T5 in Mustangs. You can put a V-6 tranny in. But don't be surprised if comes apart on you when you add a little more torque than what it was intended for.
I have T56 that is rated for 450 ftlbs torque. Cost me 2500 just for the tranny. I installed it myself on a weekend.
My suggestion, save your money and get either a Richmond 5 or 6 speed or get a Tremec T56.
Take a look at this page. Look at the torque specs. Not very much if you ask me.
http://www.ttcautomotive.com/English/products/T-5.asp