i have a 72 elcamino i' building a 383 for it, trying to figure out if i should run the th400 or install a powerglide, and what rear end ratio to run, also if i should use a locker, posi, limited slip. or what. i want to drive the car on the street and run it at the track. gas miles doesnt matter. the car weighs around 3400lbs but its more around 3000 now. it came from the factory with a th 35o and a 400 was installed with a custom length drive shaft. how hard would it be to install a powerglide? i plan on running a 3600rpm stall and spraying a 200 shot of nitrous. so around 500 to 550 on motor and with nitrous maybe 750? i want a transbrake. any thoughts or help?