Advice Needed/Chain Guard/Motor Mount Problem

I mounted the engine onto the Cruiser Bike that I have but I cannot get the chain guard to fit as the motor sits very low and there is not enough room for the top part of the chain guard to slide in.

I think that I need to have the motor mounted higher on the frame to allow for clearance of the chainguard. Is there motor mount shims or motor mount extenders that I can buy to attach so that the engine will sit snug higher up on the frame?

Thanks
Dave