just broke the drive drum in my 86 ss with a 2004r tranny. i thought the converter let go so i ordered a patc 2800 stall converter. and while waiting on the converter to show up i started reading up on these trannies and they said the weak point was the drive drum breaking the shaft. so i tore mine apart and sure enough the drive drums shaft had broke right at the end .people said the hardend ones were a waist of 2 bills. the $400 one with the billet shafts are supost to be indestrutible.my turbo buddy told me just buy a new g.m one.$55. it will be fine. i was doing donuts when it let go and he said that i had it in drive and when it shifted into second the shock of it shifting is what broke the shaft. he said if i would have had it in low it wouldn't have broke. he said he's drag raced alot of turbo's and never broke one. he said bad driving a high h.p.(my ss dyo' 450 h.p.) will break alot of ****.