Well Ted, it first depends on the thickness of the cowl. On the Ef Yak the cowl is so thin and lite that the cowl binders bottom out before the tighten down on the cowl. As such i had to sand a little of the male end of the binder so it would not bottom out before it became tite. (very simple) However if you have added material to the cowl this will not be necessary and as a matter of fact if you have added too much it may be impossible to use the binders unless you grind some material away.

You have to enlarge you already existing holes to 5/16 I highly suggest using a reamer, not a drill. Drills tend to wander, it that happens your existing mounting holes in the Fus. won't line up.

I replaced the wood screws with 4-40 screws. Now you need washers and the washer that fits a 4-40 will not recess into the cowl binder, so I drilled out some #2 washers to accept the 4-40 screw.

Then I really got anal and indexed the mounting tabs on the Fus by drilling the tab with a 1/2 forstner bit (I think it was 1/2 inch, I'd have to check) I only made this hole about 3/32 deep. I'll post a pic later if you get the binders.

John