It has a G-Team 31 inch Briggs, originally a 12.5 hp.
I really don't have a transmission, I use a 1:1 right angle gearbox similar to what is used on a grain auger, it weighs alot, but so far has been extremely durable.
The frame, steering system and front axle of the mower was all hand made, and it has a solid live axle for the rear. The hood is off of an old Huffy Sheraton (which I modified so that I could open it without taking it all the way off) and the fenders are from a Murray.