Ok, a few questions. I'ts my first ground up build so please bear with me. I got a 91 with no engine or tranny but set up for a manual. I went to a junk yard and got a 5 speed Chevy transmission. I don't know what kind of engine was in the car other than that it was a V8. How can I tell which engine the tranny will bolt to or which 5 speed I have? And also, will the drive shaft that is currently behind a 700R4 in another '91 fit the 5 speed? Any help would be appreciated. A transmission shop just told me that it was a GM and that it was a 5 speed (although I figured that out by moving the shifter around).

First we need to figure out what 5 speed you got, because odds against it being the one you need. First, does it have the bellhousing? If so, is it removable or integral? If it's integral, can't be unbolted, you got a 5 speed you can't use. Next, look at the tail end of it. Does it have drilled bosses going horizontally and transversely, for mounting the torque arm bracket? If not, this will cause hassles, at least. Next, does it use an internal rail shifter? Then, remove the bellhousing, gently clamp some vise-grips onto the input shaft, and start figuring out the gear ratios by how many times you have to turn the input shaft, in each gear, for one turn of the output shaft. The T5 you want has a 2.95:1 first, 1.94:1 second, 1.34:1 third, 1.00:1 fourth, and either 0.625:1 or 0.725:1 fifth. Check all that and report back to us.

ok, so I found out the tranny was out of an 87 Firebird with a 305. That solves that problem. Now I need to know if it will bolt to a 383 and handle 500 ft. lbs. or torque. Also, I need to know if the driveshaft from my other 91 Camaro with a 700R4 will work with the 5 speed. Oh, when shopping for a radiator, why does it matter what type of trans I have?

If its out of a 87 its probably a T5 and it will not hold up to that much power.

Would a reputable transmission shop be able to rebuild it to handle that much power?
What about the drive shaft though?

For that kind of power you'll need a TKO something or other, or a T56. Any GM T5 is going to break. There are shops that will build it to handle more power, but the T5 casing is just weak. They flex and things break.

That sucks, I really don't want to buy another transmission. Whould you happen to know how much a transmission for a 91 Camaro with a 383 might cost me?

Well I mean it depends on what you get. The cheapest option is a T56... they go for $1000-$1600 depending on lots of variables. You can get them for less but you'll want all the parts from the donor car that you can get.

You can use a T5... as cheap as tehy are... you can just drop it and replace it for $250 a pop. Not really a huge deal. They'll last for a while... it's just they wont hold up in the long run.