The manual call out for spacers on this bow are - 7/8 th on center top blending to 5/8 were the bow meets the longeron. This again is for 1/4 inch wind shield and 1/8 inch canopies . My windshield will be 3/8 and canopies 1/4 . I applied the best common sence solution and removed an 1/8 inch . Top center spacer started at 3/4 and blended to 1/2 at longeron. I will be able to adjust the heigth of the windshield bow to take care of the thickness differance at the top where the windshield meets the spline . The sides are a different matter and will have to be dealt with on assembly and fitting .