OK, did some measuring of my engine, MT-57.
With the stock standoffs I get 6-15/16 from what would be the firewall to the back of the spinner plate.
That puts the spinner plate 1/8 of an inch in front of the cowl face. What would everyone recomend for a spacer to give additional clearance. 1/4, 3/8 ??
Also, would it be necessary to drill a hole in the center of the firewall for the carb to breath easier ?
If I add a 3/8 spacer, that puts the carb opening about 3/4 from the firewall.

Thanks