C2 When ...325s got Patent No. on main case?

[Tom D.]

Medatronics (Paul C's website) indicates "mostly 1964" for Muncies numbered with the ...325 casting and the words "patent pending". Anybody know when that changed to "Patent number"? The case in the photo has P0526 on it. I take that to be May, 1965, based only on Medatronics' listing of main case numbers.

Thanks in advance - Tom D.

[Wayne M.]

Re: C2 When ...325s got Patent No. on main case?

Tom -- I've been gathering "325" case data for a while now, and one critical piece of info is the approx. date when the top bolt boss (on the maincase rear-to-tail case) went from round (like at the bottom of the case) to a larger square boss. My survey indicates this happened somewhere between 25 Nov '64 (round), and 12 Dec '64 (square). Now this change may not have occured on all mould # runs simultaneously, but I've seen no overlap so far.

Now this helps you to weed out the post-November '65 model year cases from the early '64's (of course, based on the P-assy date).

My info doesn't help establish the break point for "Pat. Pending", but my gut feel is that it ended early (in the first few months) of the '64 model year

[Tom D.]

Thanks - So I figure May, 1964.

Thanks - Yep, it has the rectangular boss on top. Based on your good reply above, I conclude that my P0526 stamp was done on May 26,1965. I also assume this was dated in Muncie, Indiana.

Why do I feel dumb at this point? Now I see the big number 5 cast into the case, right near the P-code, as well as a 5 and three dots inside a circle (not visible in this photo). Another May, 1965 indicator.

One more thing: There is a small circled 5 stamped on top of the boss you told me about.

Thanks again.
Tom D.

[Tom D.]

I mean May, 1965 - Sorry *NM*

[Wayne M.]

Re: Thanks - So I figure May, 1964.

Tom -- yes; square boss points to May '65. However, the big # 5 cast forward of the "P" stamp is the casting mould number -- I've seen anywhere from 1 thru 13, and has no bearing on the vintage. The number 5 with 3 dots in the small circle means the part was cast in the 3rd week of May (5th month); no year info here.

The small circle with a 5 stamped near the top square bolt boss is an inspector's identification stamp.

[William C.]

Re: Thanks - So I figure May, 1964.

Just to add to your collection, I have a P1219 "325" case in the shop with the first design (round) reinforcement and the Patent # on the side.

[Wayne M.]

Re: Thanks - So I figure May, 1964.

Bill, do you have any other info (VIN #) that would indicate if this case is a Dec 19th ('64) or ('63). I don't know if the Patent # was present (I suspect yes) by Dec '63 (on '64 model cars)