Technical flatty stamped #`s

Found these under intake on a 21 stud. I was hoping to see the LB but no.
Right front to back: R18-87072. MCAL. S F B
Left: 060 PS H, BSG, circled F. U
Right front of block has 21 cast.

I am sure some of those are inspectors but maybe a date hidden here or other tid bit?

 

I know what the circled F.U. signifies but i'm no help on the rest....other than a bump back to the top

 

Not all LB were stamped "LB" but were vented. Pull the pan and a main cap

 

18-87072 looks like a serial number for 32-34 ford. I'd imagine the frame the engine originally came in would also have that number stamped. Have no idea what the R before the number would signify.

 

Deuce.... the tube under the intake manifold is there. So vented I guess? The rear cap showed a brass endplay spacer without removing the cap. Wish I had removed it but I hate removing/disturbing the rear seal.

Kinda strange to see a VIN on the intake surface but sure looks like it. Then also the 060 could also be an overbore but I don`t want to remove the heads. This thing is like a swiss clock when running....

 

Tube there so its vented,good chance its an LB. The early blocks don't have a rear seal..060 is risky with these early 21 studs.'37 was better. 87072 is July 1932 not counting the 18. The R could be the Rouge assy plant.All engines were done there.

 

thanks