1966 J-56 Calipers

[Bill Braun 33186]

Re: 1966 J-56 Calipers

Joe -

I have some digital photos. You don't mind if I clog up your e-mail box?

Bill Braun 33186

[Page C.]

Re: 1966 J-56 Calipers

Hi Joe,
I came across a nos half of a left inside front a local swap meet years ago. It is the second design with no guide post in the bore. It has a casting # 5473795 and Delco Moraine. It also has a date code of 2334. Probably the 233 day of 1974
Regards
Page Campbell

[Joe L.]

Re: 1966 J-56 Calipers

Page-----

The GM #547xxxx caliper castings are 2nd design calipers. In fact, they are what some people call "3rd design", but they really aren't a different "design" from the 2nd design. These calipers were used from about 1973 through 1982. Although the configuration of the calipers are slightly different than the 67-72 2nd design, they are 100% interchangeable and all parts are interchangeable. These calipers are cast from gray cast iron rather than the nodular or ductile iron used for 65-72 calipers. That's the primary difference in them and also the difference which results in the slight changes in configuration.

While it's rare to see a year coding as part of the julian date code on calipers, I have seen it on these 73-82 calipers. That's because with the change in caliper material, the foundry also changed. The old Danville, IL foundry that produced the 65-72 calipers didn't use any year coding on the castings. Whatever foundry did the 73-82 calipers did, sometimes, use the year coding.

The calipers were manufactured, for SERVICE, into the late 80s, so the year coding on the one you saw could have represented 1974 or 1984, depending upon how long ago you saw it.