My standoff block was 1 7/16" but the resulting gap between the spinner backplate was too much - no worries - the Hanger 9 mount is slotted and it is an easy operation to make minor adjustments to the location of the BME by adjusting the engine bolt locations.

I used the 1" - 1 7/16" SWB Manufacturing standoffs to get the optimum positioning of the engine on the Hanger 9 mount. The standoffs come with 3 spacers and you use the ones you need.

A drop or two of epoxy (or medium CA) on the inside of the cowl around the bolt holes proved to be very useful to ensure the holes did not get enlarged during the process of installing and removing the cowl multiple times. This is important as the position of the cowl is how the location of the engine and spinner backplate is determined.

Also, be very sure that all 4 bolts are used to fix the cowl in place - the cowl is flexible and not using all four bolts can throw things off during the cowl cutting and engine mounting process.