Piece to right of Exhaust Manifold....

[OzFab]

I was told that they do not have a clutch for a 1" shaft where the horsepower is greater than 8.

That seems ridiculous considering most engines with a 1" shaft are more than 8hp

Copied & pasted from the BMI site for this clutch:

Specs:

1" Bore
14 Tooth
#40/41 Chain
1/4" Integral Key
Engages at 2300 RPM

Benefits:

Up to 13 HP
Bi-Directional (Inboard or Outboard)
Load-free starting
Easy to Install
Integral Key Design
Overload Protection
Sintered metal clutch shoes
Heat dispersing spring-to-shoe design