blackout Mike those are MAJOR WORDS.
If you are just going to cruise and a little play, The TKO 600 would be ok. This will also give you room to expand the power of the motor down the road. Over build the 9" with 31 spline axles and a good posi rear end. This will last a life time. With 3.50's and over drive, this should be a good combo. Car will run 12's in 1/4 mile and keep up with most street cars. 4 link rear suspension that is adjustable will help with getting power to the ground. Learning how to shift smooth will help the TKO. No full power shifts, No tranny like this even mine that is race.
I think you have a good game plan to work with. You have not said alot on the 390 build? Here is something to think about, your 390 parts could be 40 years old and see nothing wrong with them but hundreds of heat cycles. You buy a stroker kit and you get new parts that are balanced and ready to drop in the block. I have a new set of lemans rods I was going to use. They are still 35 years old in the box. The other thing is running BBC rods and bearings you get a wider bearing for the rods. This will spread out the load better than a SB ford windsor bearing on a rotating mass that is 200 grams heavier than SB. Something to think about. This is another reason for running good
oil pressure. Down side is checking the gears on the distributor every couple of thousand miles for wear. No bronze gears!!. Good basic
oil. 10w-40 or 15-40 will work fine. I do run a bottle of Lucas
oil suppliment in my motor. It sticks to all parts inside the motor and helps stop dry starts of the motor unless you add an accusump as a pre oiler 2 quart is good. I run a 3 quart. 80% of motor wear is done during startup. Have to remember that what oil pressure you see on gauge IS NOT what the back of the motor is getting. Anywhere from a 15-40 psi drop depend on clearances in the motor. This is a good start for you. Rick L. P.s. where in NY are you??