904 torque converter recommendations?

Did you forget the cam-specs on purpose?

For street;
My choice would be; ~80% of the rpm of peak torque, plus or minus 200rpm, rounded to the nearest 100rpm.
This depends mostly on the gears. Towards the high side for hiway gears, the low side for performance gears.
Thus for a torque-peak at 3700rpm, I'd be looking at 2960 +/- 200, and rounded.
So then, I'd get a 3200 for 2.94s, or 2800 for 3.91s

A cam to torque-peak at 3700, takes about 232@ 050, depending on several factors such as; the heads, the cam's installed LSA, the Ignition timing, and the cylinder pressure.
232 @050; on a 110LSA/ FTH, could be ~278 advertised.

Your results may vary.