Choosing of converter help

I've had one Ultimate converter and loved it! Street driving and track. My low power magnum 5.9 would 60ft at 1.54... I never expected it to 60ft like that. I ended up going to 727 and wasn't satisfied. I'm rebuilding the entire combo and Lenny at Ultimate will be building my converter for my CRT 904. Just my 2 cents.
what will be the best converter to my combo? The car will be most driven in 1/8 mile. waiting on my engine getting finish, the combo is 408cid , well ported W2 heads, TTi W2 headers, 830/1050 holley,10,8:1 comp, comp cam duration 296 valve lift inn 0,649 exaust 0,651 rpm range 4200 to 7400. 727 tci transmission, dynamic 9,5 3800-4200 stall, 4,56 gear, 28-10,5x15 slicks. Been reading the converter should be 1000rpm over cam starts to pull?
For this combo turbo action would live forever in general conv company’s are conservative in what they sell you A 904 would be worth a tenth.they are really tough.l like ptc also