Thank you

[Dale S.]

Many thanks to Clem Zahrobsky and John Hinckley. They were not exactly what I was told when I bought them for 15.00 ea 30 years ago. I have a 1967,327,4 sp. coupe with A/C. Can some one tell me which alternator goes on it? I have been told 37A,55A,61A,63A. also a part number if some one has it. It has a 1100742 61A 1 023 12V neg on it now. What is that for? Thanks Dale

[Joe L.]

Re: Thank you

Dale------

The "correct" alternator for your application is a GM #1100694, although it's possible that a 1100750 was alternately used (no pun intended).

The 1100742 that you have was originally used on some 1966-67 full size Chevrolet passenger cars with A/C. It may also have been used on other non-Chevrolet GM models.

Keep in mind that there are a large number of alternator part numbers and, for any given period, very few actual variances in external case half configuration. There were even fewer variances as far as internal parts go. Differences in "clocking" (relative position of the front and rear case halves) was one major reason for different part numbers for alternators which were otherwise identical. Of course, case half "clocking" can be easily changed so that one part number "becomes" another part number. Unfortunately, changing the actual stamped-in numbers is not so easy.

The point is this: in most circumstances, one can easily "re-create" an alternator configuration which is absolutely identical to the original, save for "numbers". Most alternator case halfs are anything but rare (a great exception is 1969-70 case halves which are extremely difficult to locate exclusive of the "numbers" issue).

So, from a configuration standpoint, you can achieve about 99.9% accuracy with little trouble. In fact, I expect that the 1100742 that you have is identical (or, can be rendered identical with a change in case half clocking) to the configuration of the 1100694 except for "numbers". That's because, in my mind, the "numbers" amount to about 0.1% of the configuration.

Folks pay HUGE premiums for these "numbers" when they can obtain a configuration-correct alternator for "peanuts". This mania regarding "numbers" never ceases to amuse and befuddle me and, as some folks know, I'm a "numbers-kind-of-guy"!