! have a 5.7 with a 4l60 out of 1995 chevy wt 1500. its in a 1988 GMR duravan K3500/ I bought it that way, with no electrical going to the tranny. After several hundred miles, The tranny quit working. It kicking in and out of gear. Do I need to replace the tranny? If so, what can I replace it with, that will bolt in place?