Thanks Mark, I will look forward to hear the results you get.
In my mind I would not have picked a 8" for your combination because of that I have been seeing around my area, and experiences I read on.
The Horse power and torque your motor puts out, weight of the car do help determine the converter size. The smaller converters work well with small CID low HP motors, and the thinking around here is to use a larger dia. converter to handle the HP to weight ratio, to prevent converter cavitation. which greatly reduces the converter efficiency.
My builder is building me a 10" for my 632 cid, 2500 lb. with me, Camaro. The motor makes 1000 HP. The JW 9.5" I have in it now is cavitat-ing, (not over full) and blowing throw.
So again I am sure your builder has all you correct numbers and will give you a converter that will do what you want.
JT