if the junk yard drained that tranny it is going to take a special synthetic fluid made by GM and mopar---it costs $20 a quart---if you use any other fluid your carbonfiber syncros will fall apart and it will cost about $120 for new syncros plus the labor--then you will have to put in $100 of fluid again--the nv4500 is about as strong a tranny as you will find--the only criticism being the harmonics of a cummins diesel coupled with guys that lug big loads (cummins) in 5th gear--then whine about it falling apart---GM has had great success using this trans behind gas motors...bob