My green book (Ford Bible) is buried under mountainous precious rubble, after a shelf collapse in my 'man cave' (hobby shop) Someone with the Book will answer soon enough, sorry it wasn't I. Meanwhile, I am picking up and moving stuff ac***ulated over 40 years...Hey! My 16 cyl. Nash distributer cap!... Wondered where that went...
I had a set sorta like this in a '36 3-window I had 20 years ago. The guy I bought it from said it had a '34 engine and the heads were service parts released after the war for '33-'34 Fords. The "40-5049B" is the original Ford part number, and the "1-9-46" is the casting date. (Mine had a '47 casting date.) I find it kind of amazing that Ford was producing service parts more than ten years after the original production ceased, but those were different times.
Remember...no new cars '42-45, so a '34 was kind of in the market position of a 5 year old car! There was HUGE parts demand for at least 5 years after WWII because cars had been patched up with no parts available for several years, and slow start up of new car production combined with huge demand kept new cars scarce for a while.
The Jalopy Journal
