I was gifted this 1946 WD15 this year for my birthday from my in-laws. The truck has been in the family for at least 40 to 60 years. 2 years ago, my father-in-law was able to find a registration from I think the 80's, after his elder brother died. The truck was still titled in their mother's name, and he was able to get the title. I had been oogling over it for some time, and they gifted it to me this year.
I have started what is likely to be a complete tear-down. I busted a bolt in the block while taking the head off in May, and just last week was able to get the cab off and with the help of a friend, we were able to get it out and the hole cleaned up!
While looking at the truck today, I decided to check the engine number for some reason (maybe history with other vehicles and mis-matched engines I have had in the past).
The information I have says it should be a 3 speed, but it has a 4 speed.
Secondly, the engine casting number puts this as a flathead 6 form a 1937 D5 or a 1954 Dodge Coronet!
I did measure the head and it is 23 inches, which leads me to believe this came from a 1937 and is still a 218.
The engine code is D5I-8539. I am not sure if the digit after the 5 is an "I" or a "one"
ETA. It also looks like the 54 Coronet would have had a 230, which also has the same 23 inch head,so I presume it would have been a direct bolt in to the truck for either motor?