my biggest fear would be if it had a tranz failer and is full of shavings..

but have run a many used ones from the JY with out a problem

if its known to be good(trust who gave it to you) then run it

only thing I could see wrong with it is if it got trash in it from sitting and the snout not pluged

dirt or object fell in it maybe

you could have it open and checked and tweeked for some more stall but then you would be better off starting with a reman high stall TC to begin with

reman runs around 120$ at my local tranz shop

and I have a high stall /6 tc behind my 318 for a tad more stall

good luck either way