Agree you need some clearance. After I burnt a set of Moroso wires on my setup I got the MSD adjustable boot wires. No problems since as I have decent clearance. For reference I'm running Ed heads on a B engine with 1 7/8" TTI's. The TTI's came "pre-dimpled" for the angled plug Ed heads so it was just a matter of getting the right boot angles to clear the headers.