3769973 318 Heads on my new motor

OK so here is another question. Given the my 318 is built as I described it, not having any knowledge about mopar drivetrains, if I was to find a non overdrive 833 from early to mid 70's and installed it in my car with a stock 3.23 geared 8 1/4 rear, about how man RPM will the motor be turning at 65 MPH with stock 14" wheels and tires?
And how is first gear going to feel?