The first letter is the year that part was put into production, B - 1950, C - 1960 and so on. The next digit is the actual year the part was put into production B7 is 1957. Note that isn't the year the part was made. The next two letters designate the car lines it applies to. The next series of numbers is the base number. Every part has a base number in Ford's system. Front end parts are 2000 base numbers, every 6731 is an oil filter. The last letter denotes modifications to the part typically starting with A. So a C1AZ-6731-A is and Fl-1 oil filter.
The front pinion support is a 1965 casting revision 'A', which would probably extend into 1966 unless engineering changes took place, then it would be 'B'. The ring gear is 1963 design. The WAR case was used for a number of years, and that one cast either February 22, 1960 or 1970 (if that is a zero, which it appears). The actual assembly date would be on a tag that was on one of the bolts holding the center section in.
Just the regular center section used from 1957-1964 'ish The pinion support housing is from 1965. The code on the ring gear is not 1210, what appears as the initial 1 is a shallow stamped 4. The code is C3WU 4210 B. That is a Ford ring gear part number, from the C3WU 4209 B ring and pinion set, which I think is 3.25:1, but that can be confirmed by counting ring and pinion teeth, and math. If that is the correct ratio, there will be 39 teeth on the ring gear, and 12 on the pinion. 39 divided by 12 is 3.25. Substitute whatever counts you find to get your ratio.
Oh, and open carrier, 28-spline axles. Standard passenger car stuff. Factory strong enough for about anything but nitrous and slicks.
Very close- the date like C4 actually refers to the year model vehicle that the casting was designed for, so a C4 casting would probably actually go into production sometime in 63 for installation in 64 MY vehicles. C= 60's decade, 4 is consecutive year. The car line code tells you which car line paid for the engineering for the casting, A is full-size Ford, M is Mercury, Z is Mustang etc. Last is the division, E for engine etc. Base numbers, as you said, refer to the type of casting, 6015 is always an engine block, 9425 an intake manifold. Last is the suffix that tells you what exact casting design it is. DIF was Dearborn Iron Foundry. OB22 is the date it was actually cast, Feb 22 1960. The casting number would not change unless there was an actual revision in the casting, then a new number would be generated
So who's going to explain the WAR code, and all those similar ones that were used well into the 1950s?
Some of those were used into the 70's. I think they may have been data book codes. I remember rear ends having WAR and WDC, but it really didn't directly relate to the parts system. However, you may need that code to get a correct part. Ford's part numbering system made sense since you could tell what a part was by the basic number. The rest of it didn't always make sense. Casting numbers and engineering numbers look just like parts numbers but don't directly relate to a part.
I was mostly referring to the older parts, like you'd find ECZ on Y block heads, there were the weird flathead number 59A and 8BA, and lots of other strange stuff. When I was working on a Model T the part numbers all made sense...they were T then whatever number was next in line to be used on a part.
The confusing part is that you are looking at casting numbers, not part numbers. That basic casting number might end up being a few different part numbers, depending on how it was machined and finished. The part number may be very similar to the basic casting number, but different. A good example is a later 60's FE head from a 390, same basic casting number on the casting, but one has the 8-bolt "regular" exhaust manifold bolt pattern, another has the 14-bolt shock tower/"GT" bolt pattern. There is a Master Cross Reference List that can help cross casting numbers to part numbers, but folks usually just refer to the casting number with maybe a caveat, like C8AE-6090-H "eight bolt heads" opposed to "14bolt heads".
And if you look at the number on the ring gear C3UW 4210 B it would actually indicate 1963 Econoline.
Thanks for all the replies. As usual when I was picking the car up the seller was sure it was a Cyclone even though it said Caliente on the door panels. The seller also said the rear end was a 9" with "racing gears and a Detroit Locker." Ring gear has a 3" rusted area from sitting 30 years that it won't spin completely around. I'll be cleaning that up.
Here's a good ID summary. https://thevintagemustang.com/kevingstangfordnineinchdiff/ Something you may know: if you can get a socket on the bottom two center section nuts, it's an 8" and not a 9". I wouldn't sweat it, though. An 8" is plenty strong for a small block on street tires and there is a decent gear and locking diff selection.
And that part could be used on any vehicle line, that is just the FoMoCo division that internally paid for the engineering for the part/ casting. Lots of early FE block designs were C1Ae (first year 390), some C2s (406 etc) quite a few C3s and C4s as the 427 was being constantly revised (I have a 64 SPEC 427 block, SPEC stuff might or might not have been done by unnamed individuals at undocumented shop time lol). Some very interesting C4AE blocks out there, as 64 was also the first year of the FT truck engines, so to simplify things with all the changes that year, 427, FT etc., there are a lot of '64 4.05 bore (390 car and 361/391 FT truck) blocks out there, that also have the provisions cast into them for cross-bolt mains- makes a great start for a 445 stroker if you have a set of 427 caps. C5AE-A blocks were cast with both 390 and 427 cylinder cores, but the main change was the 65-up 4-bolt mount flange, so a new number was generated- also the last mainstream center-oiler 427 block casting. 428 was new for 1966, and the block (along with a similar block with 390 cylinder cores) engineering was paid for by Mercury division, the C6ME block. The 429/460 stuff was paid for by the Lincoln line. Spread the costs around and share the wealth
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