Compact gear reducer

I am looking for a compact grear reducer for a project. I need 6:1 and
5 Hp. Right angle would be nice but not required. The Boston gear
stuff is so massive, I need something more compact, and fairly
affordable.
What I really want is the gear reducer that is built on to the side of
some small Briggs snow blower motors, but the gear is machined into the
shaft which makes it not removable. Anyone have any Ideas?
JoeV