Replacing Briggs in Wheel Horse

[BKBrown]

I'm replacing a 1971 - 190434-0638-01 8 Hp horizontal with a 150117-0123-B8
(I was told that is the closest to a direct replacement). It is for a 1971 Wheel Horse 800 Special.
The new engine has alternator and starter, but there is no wiring diagram or instruction for wiring old harness to the engine.
I can mount it and make the shaft line up, but it won't do me much good if I can't wire it and run it.

Thanks in advance for any input and information.