I've had a bunch of different brand and size converters in race cars and street and strip, my old Duster had a custom made off of the dyno sheets 10 inch Continental street and strip. It was to tight for drag racing at the track, it would push the front tires locked up on the brakes through the staging beams at 2300 RPM in low gear I ended up breaking the sprague in it after hopping the motor up enough to go from 10.69 ET at 124. MPH to mid 10.30s at 127+ mph at 3450Lbs with me in it. I put a Turbo Action SS/AH 8 inch foot brake converter in it, it picked the car up .2 ET and 2.+ MPH in the 1/8 MILE It was way easier to drive at the track and very good to drive on the street
Find a good T/A 069J 3800 or a T/A 4200 J converter or a new 8 inch from Paul at T/A
I have learned that the more HP and torque you have the larger diameter converter you need, if your under 850 HP and similar torque go with the 8 inch, if you have more HP and torque than that go with the 9 inch