Have 400 mopar with 727. car was doing 70mph, reved up quite a bit, then back to 70 on its own, then spit tranny fluid out back on exhausts. Was as able to drive off freeway, fluid is clear, no parts in fluid. Cannot find anything outward wrong. can someone help. Tranny only has about a 1000 miles on it . Was able to drive on lift. Thanks!

 

Based on what you're saying and of course without having it in front of me, I'd start with the basics. Overfilling will cause foam or air bound in the pump which could cause what we called puking. Check the fluid hot in neutral. Even 1/2 quart over can cause it to puke. It could spew out the vent cap topside back or the filler tube. Make sure the coolant lines going to the radiator aren't pinched, plugged or kinked. Over heating will cause your exact issue. You didn't mention if you have a high stall converter in it. High revving converters generate high heat. When lockup converters started being used in Mopars (mid 70s) transmission temps dropped considerably. Spinning pumping fluid creates heat.

 

Everything you've said makes good sense, except i would have thought it would have done this in the first 150 miles. Up until it gave problems, it ran great. Thank you.