I have a friend who had the same car same year same engine.. and Ofcourse same problem. His eventually got so bad that it was hard to move it into drive or reverse. His was automatic. after some time the car would not go over 35 mph because it would short out of first or second gear. he had it rebuild only for the same problem to arise again after 4 months.
I had done some research and I found that there is a solenoid of some kind on the transmission, some kind of sensor that is known to fail on those cars and causes the transmission to fail in such ways as described by you and me. Might want to look into that aswell before or soon after you have it rebuild. Hope this info didn't come to late. Those transmissions were made to handle a v8 with no problem.
I had done some research and I found that there is a solenoid of some kind on the transmission, some kind of sensor that is known to fail on those cars and causes the transmission to fail in such ways as described by you and me. Might want to look into that aswell before or soon after you have it rebuild. Hope this info didn't come to late. Those transmissions were made to handle a v8 with no problem.
