67, 427, L36 A/C lower mounting bracket question

[John R.]

Looking in the 1967 AIM, a/c lower mounting bracket #3894364 appears to have 2 mounting provisions for the compressor and 2 for mounting to the exhaust manifold. My bracket has the same part number on it, but only has 1 mounting provision for the compressor and 2 for the exhaust manifold. Is the AIM incorrect in the illustration or is my bracket incorrect eventhough it has the correct part number, maybe a later production with a change in the mounting provision?? Has anyone observed this before?

[John R.]

Re: 67, 427, L36 A/C lower mounting bracket question

Forgot to mention the page in the 67 AIM to look at, C60 section, C3.

[Joe L.]

Re: 67, 427, L36 A/C lower mounting bracket question

Looking in the 1967 AIM, a/c lower mounting bracket #3894364 appears to have 2 mounting provisions for the compressor and 2 for mounting to the exhaust manifold. My bracket has the same part number on it, but only has 1 mounting provision for the compressor and 2 for the exhaust manifold. Is the AIM incorrect in the illustration or is my bracket incorrect eventhough it has the correct part number, maybe a later production with a change in the mounting provision?? Has anyone observed this before?

John-----


You've happened upon what's likely an error in the AIM. Here's the deal:

For 1966 L-36 with C-60 a stamped steel rear compressor bracket was used. This bracket was GM #3887165. This piece used one mounting point to the engine and 2 mounting points to the compressor. Incidentally, a cast iron front bracket was used and this piece was GM #3887166.

For 1967, things changed. For 1967 the rear bracket was made of cast iron and was of GM #3894364. This bracket used 2 mounting points to the engine and 1 mounting point to the compressor. A different cast iron front bracket was also used. This was GM #3894362.

What, apparently, happened here is the 1967 AIM drawing for the L-36 with C-60 was a carry-over from 1966, although the parts and part numbers did change and that was reflected in the schedule attached to the drawing. So, what's depicted is the 1966 parts and configuration but with the correct 1967 part numbers.

By the way, the 1967 compressor mounting configuration and part numbers were used right through the end of Corvette big block production in 1974. So, only 1966 is different. Also, the 1967-74 compressor mounting bracket part numbers never superceded the 1966, so 1966 is "all by itself" as far as this is concerned. The 1966 parts were discontinued without supercession in 1972 and 1974, respectively.

[John R.]

Re: 67, 427, L36 A/C lower mounting bracket question

Joe, thank you very much, sounds like a perfectly good explanation.