I'll try not to write a book but i need to give some back ground on the deal..
Last summer a customer gave me a good working C4 to install a tail bushing/seal, front seal and a trans-go jr kit.Piece of cake right??? well summit sent him the wrong converter. It was in a box with the 1500rpm stall part number but it was really like a 3500 plus...He did not think anything about it untill it was in the car and the thing would not move. It is in a street rod with a 100 percent stock 302. So he takes the thing back out, and thats a story in it self because the entire engine/trans combo has to come out... I then took the entire transmission apart just to be safe. I only needed to replace one clutch pack. It was probably fine but while i was there i just did it. Everything air checked fine and the stack clearances were good. This transmission was rebuilt maybe 10,000 miles before i got it. The thing was really nice inside.
Now to the problem at hand. He tells me that the thing will loose reverse if he drives it just a short distance and then goes to leave. If he lets it sit over night reverse works fine, If he drives it a distance, say 15 miles or more reverse is fine. If it does the short distance deal some times he can get reverse and sometimes not... I am getting the car in a few weesk to check it out,,,,, Any ideas where to look first?????