351W EFI '90 Bronco Full Size (174,000)

I just drove 300 miles. I checked the tranny fluid and its hot and got lots of bubbles and was way above the fluid llevel line.
About 5 weeks ago my truck started to drive at 300rpm higher that usual at 60mph. It drives at about 2200rpm instead of 1850rpm like it used to at this speed since i got it 5 years ago. I had the transmission rebuilt almost 2 years ago but i know a new torque converter was not put in.
Even since the 5 weeks ago it idles higher than usual. In park it will race at 1400 rpm simetimes until i kick it down several times. Sometimes it just takes one kick down to go to 700rpm but its fluctuating between 700-800 rpm slowly and is not steady like it used to be.

When driving at highway speeds,(60mph) rpm is at 2250. It i give a little gas and it accelerates , ther rpm actually drops as it accelerates to 1850rpm which used to be what i used to get.
,but the truck keeps accelerating so i have to let off.

I got a breakout box and notice that when this happens(rpm drops to 1850(normal)) the torque convertor solenoid voltage drops to ~ 1 volt from ~14.5 volts so I assume this is locking the transmission to the crankshaft(high fluid pressure) and thus provides more torque or power transfer from the crankshaft to the transmission so that accounts for the lower rpm
Also the transmission fluid voltage is at 0.42 which seems below specs of 1.0~1.5V for curising speeds. 1.0 V is 200F so anthing below that is higher temp. Does this account for the bubbles. Is the tranny fluid boiling?


I checked all vacuum lines, replaced the IAC, changed the plenum gasket, checked vacuum lines one by one and cant find any leaks The timing is set right too. EGR valve ok.
I get no computer error codes from the computer.

Why is the rpm's so high at highway and general driving by 300rpm.?
I dont want to damage the transmission but high fluid temperatures.

Any ideas appreciated.

Thanks