Handy Andy Have made all my own HEI's I use 1/2 inch machinery bushings from the farm store,mostly important to have space up and down when it's clamped to the block,be sure there is oil clearance where your gear rides on the block. To avoid cap interference with the side of the engine I make an aluminum spacer to raise it up about an inch. You'll find sludge build-up on the shaft will make it hard to get apart,like for a pick-up coil change,once apart then you can clean it up.
