distributor

if it has a cam lobe of half the number of cyl and has two sets of points. one set of points fire half the cyls, and the other points fire the other cyls. the trouble is if the points are not syc to gather you have half the cyl firing at one degrees and the other firing at a different degrees. this WILL destroy the piston. i had one on a 413. the points kept slipping throwing the degrees off, it destroyed the pistons.