O.K. guys ..... here's the answer from the President (Marc Kaufman) of Old Toledo Brands ...... "It's an arbitrary number that the design team put on a t-shirt once and it's remained ever since" ..... sometimes, you wish you didn't know the answer. Maybe you guys can associate something...
I am in the process of selecting parts for this upgrade; everything is decided except the coil. I prefer to use a canister coil so I can reuse my stock coil bracket. Terry's parts list has F503Z AC Delco coil....I have found a F502Z (Ford F-150 300 CID I-6) that is a canister type but I do not...