Spyder 0069, Did you have to make any modifications to the engine mounting box or firewall to install your OS .91? I am putting one of these Zeros togethor and have been doing some measuring for a Saito .72. It looks like the crankshaft will be sticking out of the cowl about 3/4" too far with the original set-up of the engine mount and mount box. Any information will be helpfull and will be appreciated.

Thank you, old bird.