Quote:

Do you guys think it's a valvebody issue?



It's an issue CAUSED by the valvebody.

The 727 walks a very fine line on overlap , which is what you are seeing. The factory went to pains to make it as small as possible, when you increase line pressure, change clutch front pack clearance, change the lever ratio, change band adjustment and change spring count in the front drum you change that oh so delicate shift timing from the factory setting.

Now you have to deal with it. Playing with the band adjustemnt is the easiest way to try to fix it.