That's no joke! Initially it should be in the ~180FWHP/ ~210 torque range, but will be just a few parts away from going over 300ft lbs of torque.
The GSL-SE stuff is getting scarce, and I'd be stuck with ~4.08 or so gears. Ring is about 7" on the GSL-SE, so not very strong. They also sport small 26 spline 27mm axles , vs 28 spline 32mm axles on the small ford 7.5/8.8
Tire choice is likely going to let any axle I pick survive, but if I get aggressive and have it spin and then hook, I don't want to have to worry about it.
It looks like with all factory parts (so less than $200 spent including disk brake conversion) I can make 7.5 or 8.8 ford rears come out to ~53.6, 54.6, and 55.6" widths WMS to WMS. I'll be playing around with wheel widths and offsets this weekend to pick out which of these is going to be best.