there was a companyi think it was cross fire that had caps like that. but not flat. msd used the and old ford flat head cap on the crank trigger distributors. but fired stock for your engine .i think mallory had a flat cap like this on the YL tpy distributors but this was verry long time ago. and the ford flat head will not fit on just any distributors you may be able to do something with the YL and the ford flat head type cap and alot of work .call msd or mallory