Any info on this 260 block?

[Dan Case]

Casting date or assembly date? Casting dates are cast into the blocks in raised letters. Assembly dates are stamped into machined surfaces. The typical engine assembly date might be a between a few days to months after the casting was produced with a week or so being typical. Bob Mannel's book is a fantastic technical resource for 221/260/289 Ford engines and I highly recommend it for anyone working with these engines. There is not a table in the book listing when manufacture of individual parts started and stopped but Bob frequently mentions time frames that significant things were introduced into the assembly of new Fords. He indicates that the 260 engine was introduced in February 1962.

The XHP-260 (Ford lab built prototype performance engine) that remains unrestored and almost completely intact does not have an assembly date code stamped or painted anywhere. It started off being engine #2 but was renumbered #4. The block has both serial numbers on it. Only some of the prototype parts used in the engine had any kind of date code for their fabrication on them. The few dates that there were are widely scattered. One key protoype part was dated early May 1962 so engine assembly had to be mid May 1962 or later.