COM 12-417-8 Comp Cams XM270HR Camshaft .495/.503, 218/226@.050, 112 LSA, With this cam, Can I use a stock distributor off a 5.0L Merc engine on my 383 without changing the gear?
I think you are going to have to email the vendor for that information. Compcams lists your cam as needing their 12200 distributor gear but do not list the gear ratio of it, nor do they list it on the cam information.
Good luck