Cleveland engine plant, check.
Five bolt bell housing HP289 engine assemblies were given sequential numbers by Ford for the 1963 and 1964 model years. Standard HP289, i.e. not counting prototype or pilot preproduction, engines wise that meant engines shipped to a vehicle assembly plant between March 1963 and July 1964. This includes Shelby American, Inc. for new Cobras. Only HP289 engines were given sequential numbers stamped into a tooling pad on the LH rear of blocks.
As we understand it Ford assigned numbers to engines as they were being prepared to shipment to a vehicle assembly plant. The sequential numbers were not in strict order of engine assembly timing. Ford stopped numbering engines as to what was for them the last of the 1964 model year engine shipments. Ford made forty eight each five bolt bell housing engines for Shelby American to install in new unfinished Cobras in August 1964 and they were not numbered by Ford.
Bob Mannel has been collecting engine numbers and engine assembly dates for many years. He has data represented in a large chart covering 1963-64 HP289 production.
Otherwise, in the manufacturing process of taking a raw block casting and doing the work to make it a cylinder block assembly with main bearing caps various things were stamped into various places on blocks. Bob Mannel told me most of these stamped in markings meant nothing to Ford past the engine plant operations.
The information restorers and owners like to record includes block casting date, cylinder block assembly date, engine assembly date, and for 1963-64 HP289 engines the sequential number.
Casting date = by casting number, literally cast into the metal
Block machining and assembly date = on oil pan rail, covered by oil pan flange, stamped in
Engine assembly date = on block in front of LH cylinder head (if a block has had its decks milled this number is usually cut off also), stamped in
1963-64 sequential number = LH rear tooling boss, alpha characters found in that location were not part of the sequential number, stamped in
Other factory serial numbers? Shelby American (Cobras, King Cobras, and etcetera) and Ford Advanced Vehicles (GT40 MKIs) usually added a race team serial number to complete racing engines they prepared and installed. These numbers were used in internal documents like dynamometer test reports.
There was nothing special about raw block castings that went into production HP289 engines. We believe operators inspected raw castings and chose casting defect free ones to be included in cylinder block assemblies were the heavy duty main bearing caps would be added. Installing the thick caps made it an assembly ready to be built into a HP289 engine assembly. Any good block could have been converted to the same physical specifications to prepare it for a HP289 engine assembly. What makes any engine more valuable, to some but not all people, is having the car it went with also. Ditto any other part. Example: If I could find "the" carburetor that Ford installed on the engine in our black car in 1964 it would be worth maybe $X in the market and maybe $2X to me just to have "the" carburetor Ford installed and not just a similar one.
