After taking the body off my 64, I was inventorying the mount hardware and something doesn't make sense.... Here's what I found:
Radiator support: 3 horseshoe shaped body shims welded to the frame on each side.
Mount # 1 (at firewall): No rubber, a couple of shims and one aluminum spacer on each side.
Mount # 2 (under door sill): a couple of shims and nothing else.
Mount # 3 (in rear wheel well): some shims, rubber donuts above (inside the access) and below (between body and frame).
Mount # 4 (near gas tank): Rubber domuts between body and frame and below the frame mounting.
Middle mounts (center of body near inboard seat belt attachments) 1 thick flat washer on each side between body and frame.
No mount provisions at all at the outboard seat belt locations.
It appears that I have some sort of mix between 63 and 64 body mounting hardware. I doesn't match anything in my 64 AIM. My car is an early 64 (Nov 63 build; #105578). All mounts had what appeared to be reminants of tape holding the shims and aluminum spacers in place, so I am assuming that these are original.
Anyone have any input on whether this is correct or not?

 

Sir:

Your description of the 1964 body mount parts sounds authentic to me. Although I’m relying on past memory (prior to 1979), I did dismantle several 1964 convertibles and they all had that half inch thick Aluminum spacer at the #1 body mount. As a chronological reference, I had not seen it used before on earlier models. In the Northeast they often were very corroded and Swiss Cheesed with a crumbly White powder (Aluminum Oxide or rust).

Those Aluminum spacers (GM part # 3842911) are not unique to 1964 and are also shown in the 1965 AIM, however I cannot recall if they were a common feature throughout production for later model years. 1966 and 1967 AIM’s show the typical 2 piece rubber mounts. However, in 1968 and 1969 those same exact Aluminum spacers reappeared under 6 of the 8 body mount locations with a slightly different solid Aluminum spacer used at the other 2 locations.

Your description of the #2, 3 and 4 content sound perfectly normal and original to me also. Those additional inboard mounts on convertible also used a different cushion and as you found some totally lack that cushion.

I honestly think that some reproduction parts have influenced the market in an un-intended manner. What I mean is that some folk think that the repro part is right and that their car is wrong because just about everyone sells or uses that repro part. If the repro kits have influenced you, it may have colored your view of what is authentic. Some reproductions are a compromise between authenticity, safety and manufacturing limitations. Please understand that I’m not disparaging anyone’s reproduction body mount kit and I do not produce a competing item to those mentioned.

Geoffrey Coenen
NCRS #2473
NCM Lifetime #105
Precision Valley Corvette Museum Charter Member #20 (I think)
Retired #1 56, 63, 67, 68, 68, 69, 75, 99 and I want more! :D
Wanted: 1969 L-89 conv (no project)

 

Geoff,

Thanks for the info. I've gotten a few other replies with the same conclusion; everything is as it should be.