[oldchevy1956]

I have a restored 56 chevy that I finished last November and I have been working out the 'bugs' over the last several months. I have a 327 that has mild performance build, and I have a rebuilt 700R4 transmission (1989 version). The transmission will work fine and shift 3 times and go into overdrive when I switch it on so basically the transmission is doing great. But when I am really stepping on the accelerator the 2 to 3 shift is not normal in that is appears to over rev the engine almost like it slips into nuetral for 1/2 second? Fluid level is okay. Any ideas? I did intall a B&M shift kit which I can get the exact model if necessary, and that did help some but not solve the problem.

[Speedshift_Sam]

Had a problem similar once, in a 1988 GMC truck. On the downshift, it slipped like crazy for a second or two, then snagged, sometimes, quite hard. My problem was that the dumb thing had over 300 thousand miles on it and shortly after went pop, no gears at all.
This however is a bit more perplexing. I've had gummed up valve bodies act like that, also had converters with too high of a stall rpm do it too.