Bought a 91 700r4 for my 83......When I ripped open the filter I found a piece of rubber about 1/8th of inch wide, and two inches or so long, very thin....
I'm sure this can't be good....any idea where it came from?
Should I run it? The guy I got it from said it worked good before hand?
Advice?

 

This sounds like part of a seal from one of the clutch packs. Give the transmission back, this is not a "good sign".

 

I called the guy I bought it from....He said he put a thin coat of black rtv silicone on the filter seal " to help it seal" He insists it shifts and operates perfectly fine....................I have been around the block and I know talk is cheap....but I know where he lives. LOL This Camaro is a play toy for me not a daily driver so I'm gonna throw that tranny in and see what it's like....If it's no good I'll put the THM350 back in until I get the 700r4 rebuilt.

Thanks for the advice.....