Ok i have done some reading but im trying to figure out do i want to use a non-lock up or a lock-up torque converter? An what is the diff?

 

IMO, the lockup is the way to go. Unless, of course, you have a dedicated race car, and mileage is of no concern to you. Then again, I would still go with the lockup. My converter is a 9.5" 3400 stall, and still retains the lockup feature.

 

Lock up converters have a plate with friction material that "locks up" the internals, allowing the converter to go 1:1. This eliminates all internal slippage resulting in huge heat reduction, small rpm drop and increased fuel milage (when locked up).

Non lock up converters do not have this plate, therefore no ability to lock up the converter. They are lighter because of the lack of plate.