overheating on 1998 Dodge Ram Van 1500

My van is overheating(boiling) within 10 mi. of driving. Ive replace water pump, completely removed thermostat, and flushed radiator. The transmission isnt shifting into 3rd unless the rpms are way way high and even then it may not shift. Is running in high rpm trying to stay up to speed causeing the overheating...and would a shift selenoid cause the transmission problem?

Asked by for the 1998 Dodge Ram Van 1500
The high RPM would be cause for the overheating. And a shift solenoid could be cause for not shifting. Do you have a check engine light on? a scan of the codes could point you in the right direction of the needed parts. Also check condition of your transmission fluid if it's brownish colored or smells burnt change the filter and fluid. You may also try a addative like Trans-x, Dr. Tranny it may help!