Thanks for all of the information, I will reach out to Fatsco and see what they advise. I have ordered the GMC manual and Supplement covering the transmission so that should help. Looking at the H-M manual for the Chevy and there isn't any filters for the fluids and they recommend changing them on a regular basis, every 25k. I remember when driving it that first to second was very smooth but second to third seemed like a big jump and was very noticeable. I thought that it was due to the gearing and that there was a big jump, plus the motor had a miss on one cylinder which I thought also contributed. However it was smooth from third to fourth so maybe it was the trany? I am going to continue my research and get an estimate to rebuild it. Thanks a lot for the help.
