I have a 1999 Chevy Silverado 1500 with the 5.7 it is Rwd the original transmission is toast bought a used transmission (big mistake) long story short transmission didn't work so I'm trying to figure out witch complete rebuild kit do I need and witch is the best I've searched online but there is alot of parchel rebuild kits I'm just lookn for the best and right one for my 4l60e transmission

 

are both trans having the same issue? could this be a computer problem?