Thatnks for your reply Crossley. My main concern is that this trans was built to withstand hard use behind my engine. I damaged third gear components twice and had to have the trans redone each time until they finally got it right and it held for 13 years. I want to take any and all steps available to be sure that this trans will hold up in the future.
I love my car and I try not to abuse her too much. Friday was her first trip to the dragstrip. I was so pleased with how she accelerated, then no third gear. Now I'm heartbroken that I broke her. I already spoke with the guy that built the trans before. He wants $1,500 to up date the unit with the latest hi strength parts. It's a good price but i just don't have it to spend right now. I'm a master mechanic but I specialize in engines and electronic controls. I have little experience with automatic transmissions. However, I've been studying and I think I can handle this okay. Plus, I need to get over my reluctance with these things and I hate having a part in my car that I didn't build myself. I worked with a great trans builder for 2 years and we did some hi HP 4L60s. I remember what was done to beef those up, like one sided clutches, 5 pinion planets and hardened reaction drum.
I just want to be sure I have this straight before I go into the unit. The upside is that the fluid still looks good so I don't think I smoked things too bad. The trans shifts perfectly withy its current valve body tuning. It is set up for auto/manual shifting and holds every gear to 6,800rpm. It also holds overdrive at full throttle above 80mph. Therefore, I don't need to worry too much about the valve body, beyond cleaning and checking. I will check out the pump, all bushings and thrust washers, and replace all seals. If there is anything else you can can think of, please let me know.