My mate is having a custom converter built over here in UK and would like some advice on stall speed. Car is 69 satellite with rebuilt .060 over 440 8.5 to 1 compression, 906 heads, mopar 484 cam, open plain manifold, 750 double pumper and headers. Manual shift torque flight 8 3/4 with 3.55's. Has 9 x 28 inch slicks, currently running stock converter, would appreciate some suggestions on stall speed. Converter company has asked him for horse power and max torque rpm figure. He would like to get it into the 12's, running low 13's at present.

If this will be strictly race, then stall should be about 1000 rpm lower than shift rpm. For a dual purpose combo, tighter for some lockup for cruising. You will lose some ET with a tighter converter. It pretty much boils down to how much slippage you are willing to tolerate, so be sure and give the converter builder an accurate description of what characteristics you want.

You say it's running low 13's........at what speed??

terminal speed is around 105, 107 best
he shifts at 5200 rpm

My car is very similar to yours except mine is a 68 and has a Comp 292 and 3.23 gears. I was running in the low 13s with a Neal Chance 11 inch 2500 stall converter. Changed to a GER 10 inch that stalled about 3800. With some other minor changes( added carb spacer, changed from 750 vac to DP,dropped about 75 lbs)ran mid twelves with a best of 12.35 at 106. GER converter(cracked flex plates regularly ) has since been replaced with a Dynamic 9.5 but havent run it.