[Doc Watson]

In 1968 production of 302 blocks in Mexico using the original reworked tooling that produced 289 hipo blocks. They have a higher nickel content with the thicker main webs. Somewhere on the block there is a M to denote
that it was produced in Mexico such as 302M. Ford used these as factory replacement engines for warranty work.If you find one, you have as about as beefy of a 302 block you can find in factory form.They use HIPO style main caps. They are considered to be thick wall castings similar to what was produced in the states prior to 1974. Examples of differences between late model blocks and the thick wall castings are blind holes(early) vs open holes(late) for the main cap bolt. When you see the late models split in half it's at those bolt holes. The other difference is in the webbing near the mains. The early blocks are noticeably thicker than the late models. Lifter valley says Hecho en Mexico.