72 LT1 brake calipers

[Jon S.]

I'm posting the question for a friend, so I don't have alot of details. He is asking if there is any correlation between the casting numbers of the calipers and the build date of the car? Any other date markings that should appear on the calipers? I have the judging manuals for 68-69 and see nothing in there, but don't have the manuals for a 72.

Thanks in advance,
Jon Strachan #10673

[Craig S.]

Re: 72 LT1 brake calipers

Jon - these are not judged, but, there are different casting part numbers for the calipers for different years. 65-66 were unique, then 67-72 were another group of numbers, and finally 73-81. There have been posts on this in the past and you can get the casting numbers from the archives....I belive Joe Lucia has posted them in the past. There have been discussions on the apparent date codes but apparently the numbers are not julian date related as some go beyond 365 so I don't believe there is a definative answer....Craig

[Craig S.]

A copy of a post by Joe Lucia last year

Jon - here is the post I was referencing. Somewhere, I have the actual casting numbers from Joe for each half, front and rear. I will try to find them.

Re: One problem with date codes
Joe Lucia -- Wednesday, 19 December 2001, at 2:22 p.m.

Mike, et al------

Yes, transmissions do use an unusual "julian" date coding system. However, this coding is part of a transmission code stamping which includes other information. Using ALL of the information and knowing the coding system, one is able to determine precisely when a transmission was built, where it was built, what model it is, and other information. The "julian" date code used on the transmissions, by itself and exclusive of the other information stamped with it, is relatively meaningless.

In the case of the calipers, the only apparently meaningful and "date-like" numbers to be found are the 3 digit sequence with the "screw-heads" at either end. If they are a traditional, or evn non-traditional, "julian" date coding system then they lack reference to a year. Consider that the known-original calipers from my original owner 69 have the following "codes":
196, 189, 127, 189, 195, 220, 177, 183. Now, given the mid-September, 1969 build date of my car, these codes could reasonably represent "julian" date codes from a conventional system in which January 1 was coded as 001. However, considering that even using the NCRS "rule" of castings preceding the build date of a car by a maximum of 6 months (which is generous since the vast majority of castings originally used on cars will not be anywhere near the extent of that time frame) AND assuming that the "codes" seen on the calipers are something other than a traditional "julian" date code and somehow include the year, then all of my calipers would have to have a 1969 casting date, or a "9" somewhere in the sequence. Only four caliper halves do have a "9", though, and, even at that, it is at varying positions in the sequence. So, I really feel quite confident that no year is coded on the calipers in this sequence. Although there are a few other numerals to be found here and there on my calipers, none are a "9".

Although, as I mention, the "codes" on my calipers would be consistent with the notion that the coding is a conventional "julian" date code, sans reference to year, there are other things which make me doubt even that. As Gary mentioned, some of his calipers have numbers too high for a conventional "julian" date coding system and, actually, too high for even a "transmission-like" "julian" date-coding system. It also so happens that I have a good friend who is in the caliper remanufacturing business. I have had the opportunity to examine many cores in his shop. I have seen a fair number with "codes" higher than "366", the highest number which could be used in a conventional "julian" date-coding system.

Beyond all of this is this inescapable reality: even if the 3-digit codes found on the calipers are a conventional or non-conventional "julian" date coding system, without there being any coding on the caliper half representing the year , the "codes" are rather meaningless. Specifically, within a caliper casting number series and considering the normal NCRS/NCCB "6 month rule", HALF of the calipers in existence would be "correct" for any given Corvette year model which used a particular set of casting numbers.

[Craig S.]

Re: A copy of a post by Joe Lucia last year

I found this in a text file I saved from the past:

Re: 67 Disc Brake Caliper Numbers

Posted By: Gary Beaupre

Date: Friday, 12 October 2001, at 2:41 p.m.

In Response To: 67 Disc Brake Caliper Numbers (Gary Cox)

Gary,

The following casting number information is from a posting by Sal Carbone a couple of years ago. I don't

know when in '67 the switch from 1st design to 2nd design occurred.

Gary

1st design (1965 thru early 1967) fr. outer 5465952 fr. inner 5465954 rr. outer 5465905 rr. inner 5465902

2nd design (early 1967 thru early 1972) fr. outer 5452273 fr. inner 5452270 rr. outer 5452284 rr. inner

5452281

[Jon S.]

Re: A copy of a post by Joe Lucia last year

Thanks for the info Craig. I believe that is exactly the info he was looking for.

Jon