My question is what et are you capable of running with the car. That is how fast do you want to go and is your car built to the rules to run that speed.
We build our drag cars to run in certain classes knowing the rules, et and speeds to run. Knowing that info, we then build the motor, tranny, rear end and install the correct tire size to fit those rules and specs.
Your question of "rear end gearing, 373 or 410 for the pinto ?" does not provide enough info for anyone to give you a proper answer.
So, fill us in on the rest of the story......
As a side note, I will be attending the NHRA GATOR NATIONALS in Gainseville, FL in March to help a few local racers who attend that event.
Dick