Jerry, not trying to talk you out of using the six bolt hub on the 5.8 (would look pretty cool on the D7 though) but will give you my comments on the single bolt adapter. When my Brison 5.8 was brand new I bought a single bolt adapter from Gary at Brison. It mounted with 6 10x24 tapered flat head screws. Yes, they are small but very strong. I did remove two opposite screws and used two 10x24 socket cap screws with counter bored holes in the prop to keep the prop from turning on the hub. I have been flying my Corsair with this engine (see post #11 above) for over 3 years with zero problems. This has been an excellent engine and should be really good in the big D7.

Ken