Question about #3998438 AC Manifold and Muffler Assembly

[Michael B.]

The JG states that the manifold block on this hose assembly was rectangular, and that is exactly what is shown in the 72 AIM on page C60 D1. However, on page C60 E6 the drawing shows the manifold block as the binocular style. This binocular style drawing also appears in the 71 AIM on page C60 E7. I'm curious why the difference, and if the binocular style was never used in factory production, why would that drawing appear as early as the 71 AIM?


Things that make me go hmmm!


Mike

[Bill C.]

Re: Question about #3998438 AC Manifold and Muffler Assembly

I think that 454 cars with AC had the rectangular block at the compressor head.

Small block I am not 100% sure.
The service replacements are the binocular shaped block.
Just not sure of the assembly line style on the 350

[Michael B.]

Re: Question about #3998438 AC Manifold and Muffler Assembly

Bill,

Most small blocks I've seen have the rectangular shaped block also. As you said, the service replacement hoses all have the binocular style block which results in a Configuration and Date deduction. I assumed the binocular style block was introduced at a later date than what was used in 1972. That's why I was surprised to see a drawing of the binocular style block in both the 1971 and 1972 AIM's.

I'm wondering if it's possible that both styles were used in production? Obviously the binocular style block was in existence in 1971 as the page with the drawing is dated 4/13/71.

Mike

[Terry M.]

Re: Question about #3998438 AC Manifold and Muffler Assembly

Bill,

Most small blocks I've seen have the rectangular shaped block also. As you said, the service replacement hoses all have the binocular style block which results in a Configuration and Date deduction. I assumed the binocular style block was introduced at a later date than what was used in 1972. That's why I was surprised to see a drawing of the binocular style block in both the 1971 and 1972 AIM's.

I'm wondering if it's possible that both styles were used in production? Obviously the binocular style block was in existence in 1971 as the page with the drawing is dated 4/13/71.

Mike

I believe there are some things in the AIM drawings that are not PRODUCTION illustrations:
Radiator Hose clamp style == the tower clamp continued in the drawings even though the worm style clamps were used in production beginning in late 1969 model year. The part number changed, but the illustration didn't.
The cotter pin to retain the slotted trailing arm toe shims was first illustrated in the 1969 AIM yet it didn't enter production until the last week of 1970 model year, in spite of the holes being in the frame for the cotter pin.
There are numerous fasteners that are illustrated with a head configuration that was not used in production.
And now we have a different illustration of the shape of the AC muffler block.
Stuff happens. Remember the line workers installed the parts that were supplied to them by part number, not by the AIM illustration.