Like Don said, these suffer in the differntial department - and may have something like a 3.00 ratio and a 4431 (unsprung probably) weighted car that in actuality was probably closer to 5000 pound is a recipe for being doggy on the hills. I driven even newer rentals out I70 towards Vail - and been passed by semi's.

http://automotivemileposts.com/tbird...fications.html

You said the bore readings don't match - C7ME-A says that the block is:

C= 1960's
7= 1967
M= Mercury
E= Engine
A= Version

http://mustangtek.com/FordDecode.html

Which would tell me that somewhere in the cars life the engine block at least was replaced by a 1967 Mercury, and it MAY have been a remanufactured engine with a camshaft of unknown performance characteristics and with a set of pistons that may have a different compression ratio used with that particular set of heads. Possibly a set of stamps exist on the block somplace that will identify it as a reman, but not necessarily. Some engine rebuilders do a batch of similar engines at the same time - and not necessarily do all of the "correct" parts end up together.

When you dig deeper, keep in touch