Look above the
oil filter for a block casting number. Below is what one of my books says. Also, I have heard that if you pull the freeze plugs and look inside at the outside of the cylinder wall, they used to cast "428" on the outside of one of the cylinders. Fact or fiction? Can't say, but I recall seeing a pic once.
C1AE-H, N or V: 61 390 Police Interceptor (PI) w/mech cam
C2AE-BC or BE: 62 390 PI w/ mech cam
C2AE-BR or BS: 62 390 PI w/ mech cam
C3AE-Y, K or KY: 63 390 PI w/ mech cam
C3ME-B: 63 390 PI w/ mech cam
C4AE-F: 64 390 PI w/ mech cam
C5AE-B: 64 390 PI w/ hydraulic cam
C6AE-F: 66 428 PI w/ mech cam
C8AE-R: 68 428 PI w/ hydraulic cam
Hop this helps narrow it down a little. Good luck.
