I did some reseraching and C40E-6015C looks like a 289 designed for Fairlanes during the year 1964 in the Cleveland plant. So, a 289 block with 302 head and a 351W cam? Does this combo make this motor mother of all bastard engines?
more than likely that was a D4OE, im not sure but i dont think ford casted a c4oe block, the c3 casting was a 5 bolt bellhousing and c5 was six. i pulled a 289 out of 64 fairlane and it was a c3oe they just carried over the engine on that one.
but if that is a 74 block it has a greater piston to deck clearance at tdc not the most choice block for a 302
At this point, I really don't care what it is as long as it runs good. I'll just replace it with a crate engine (with matching parts) when the old engine gets tired.
C4 meand 1964, C5 meand 1965, C3 means 1963. C refers to 1960 and then the next number is the year in that decade. D4 means 1974. A 1986 block for instance would say E6.
This sounds liek quite the combo you got there I have gotten owned on the subject of the cam swap changing the firing order previously. its just somethign that happens to work on these engines, I wouldnt go trying it on other engines though.