I have a 4l65 with a 3600(Jegs brand)(I know i get what i pay for,but Jegs convertors have taken me into 10's in a Monte Carlo) When i first installed it, it hit hard off the line. after about a week of just normal driving it started doing this- street- If i accel. hard from a dead stop its fine. when i stop and try to go again it wont go. it gets up to around 5000rpm to just get rolling. -track- if I do a burn out above 4000 rpms it just spins 5000rpms to just get it rolling. and it doesnt move fast. the car crawls. but if i keep the car below 4k rpm for a burn out. i stage it around 3200 it lauches hard but after a run ........5000rpm to get to rolling. I think i have basically blew trough it. b/c i am spraying on the stall. Does anyone have any other suggestions?>

also after about 30mins of highway driving my speedo sticks. I have no clue about this>

 

i believe your stall has been ripped to shreads by the nos bc that just doesn't sound right.

 

sounds like fluid is low, or its blown apart...

 

input sprag does it do the same thing in drive ?
performabuilt.com

 

it only acts up when i get into it hard. under regular driving its fine. I prob just ripped the vert to pieces