trans cooler?

This 904 was built by a local shop for a turbo set up. We now have over 100 passes on this without turbo. The converter is a 3200 10"? We noticed after 20 passes or so the shift from 2nd to 3rd was allowing the motor to rev up a little befor going into 3rd. It stayed that way for the next 80 passes. This also has reverse manual valve body.
Now the problem is we installed the cooler filled the fluid back up took it for a ride. Taking it easy till temp was up. We started a G-Teck hp and torque test trans acted like I pushed the cluch a little and dont have one :angry7:. We re-checked the fluid it was full. Would the mounting of the cooler matter this sits a little higher then bottom of rad now. Oh it happens in second also and during staging it bucks like a bronco with the motor running smooth. Thanks for any help you can give Don