1942 Mercury heads
These are the TWO different types of 1942 Mercury heads that I have ever seen:
on the upper back side in the center, or more often to the left front edge (or rearward edge), is embossed 29A-6049 or 29A-6050
and on the front side in the very center, between the 2nd and 3rd spark plug hole, and in between the two studs is 29A-LH or 29A-RH
on the other type of heads the backside is the same as above, but on the front, the numbers are in between the 1st and 2nd spark plug hole and higher up, below the first stud, and are embossed with 29A-L or 29A-R (the H has been dropped) On a complete motor with the oil filter in place you CANNOT see 29A-L The oil filter bracket covers this.
I have heard that there might be a 3rd type, but it has not yet been verified, that has no numbers on the front, but has only the 42 part numbers on the upper rear 29A-6049 or 29A-6050. I have never heard of any with raised numbers like on other years.
This may be what was in the 1942 and 1943 heavier trucks and buses that have the 100 HP Mercury engines. I don't know. I still have yet to research this and verify. They may have come with the very plainly marked heads listed above.
By the way, the correct engine, 42 Mercury only, 239 cubic inch, has the raised intake deck (like a 1941) but with the factory milled relief between the cylinders and the valve area. This was the basis for the 45 to 48 postwar 100 HP motors and why Ford then used the Mercury 99A VIN numbers for Ford cars and trucks. These 42 heads also have the larger volume CC that the postwar heads copied. The correct colors for these heads and motors is the Dk Blue (not the dark green or silver in the following photos)
Compiled by Mercury Ed the 42 nut
