I am in the last stage of my engine swap on my 69 Camaro the MSD dist. had a bronze gear on it for the roller cam now that i have switched to a flat tappet cam i need to go back to the stock gear how do i know if it needs shimms or not?

 

Once the gear is mounted to the shaft you measure the gap between the gear and the housing. There is a washer installed there normally. Chervolet used to make a shim kit but I think that they no longer do that. That shim kit was simply washers to fill the gap between the gear and the existing washer. I do not remember the clearance specified but I sort of remember it being in the .0035 range.