So, I have a 94 T56. It's not a 93 because it has one more electrical connection on the case (CAGS I believe), and the guy that sold it to me swore up and down it was a 94.

I called Rockland Gear today, and she asked me what input shaft it was, or if there are any markings on the transmission... Unfortunately, the guy scrapped all the info off and painted the transmission.
She asked if it was the 27 or the 31 spline input shaft (I'm assuming by this she meant the portion of it that is inside the transmission)
I thought they were all 27 on that side??

Any way I can externally identify?

I'm a bit miffed, swap time was very close (like in the next 2 weeks) and this may really throw me off... Either I'll end up needing to find a new transmission. And even if the one I have is good to go, they're waiting on input shafts for their kits 2-3 weeks, so it will be a month before I can get the kit in.

 

You could have posted pictures.

The LT1 T56 looks the same 93-97 other than the CAGS and identifying numbers on a decal (up top) or metal tag (bolted down with a tailhousing bolt.)

The gear of the input shaft is 31 tooth 94-97 and that front plate needs to come off to swap them anyway. (In addition to re-setting bearing clearance.)

What do you have so far besides a trans?

 

I was pretty sure the CAGS wasn't there on a 93 so when I picked it up I checked it was on the transmission... But the phone call I made got me worried. I knew the sticker on the top was gone due to the paint the guy put on it.
However, I checked when I got home from work, found a metal tag ending in 009 which is a 94-95 T56 which means I'm good to go with the properly splined input shaft.

Right now I have the T56 and the LS1 in the garage as well as the LS1 Bellhousing.
The wiring harness is 90% complete, just need to wire in fuses and relays.
Computer is being sent out this week to be programmed.
I have all of my mounts/brackets, throttle cable etc etc currently on their way from Hawks.
Gauges from SpeedHut are being made and will be here in a few days.
I'm about to order my clutch kit.
Basically, nearly everything I need is here or almost here.

Tremec is back ordered on the input shafts that Rockland Gear uses in their kits, so as soon as they get the shafts, the kits will get sent out.