C-3 motor mount fit

[David L.]

Re: C-3 motor mount fit

Owen,
I found a some photos of a NOS 3990916 motor mount on the web. GM 3990916 is listed in my 1972 Corvette Parts Catalog for 63-72 Corvettes. As per Chevrolet Parts History (for service parts) GM 3990916 replaced GM 3886466 in Mar. 1971 which was used on early models. GM 3990916 was replaced by GM 6258154 sometime between jan. 1976 and Dec. 1981. I once has a pair of 6258154 mounts and they looked very similar.
Attached is a photo of the mount as well as the instruction sheet and list of applications. Note that the Corvette models are not on the list.
BTW, I sent you a PM.
Dave

[Joe L.]

Re: C-3 motor mount fit

Owen,
I found a some photos of a NOS 3990916 motor mount on the web. GM 3990916 is listed in my 1972 Corvette Parts Catalog for 63-72 Corvettes. As per Chevrolet Parts History (for service parts) GM 3990916 replaced GM 3886466 in Mar. 1971 which was used on early models. GM 3990916 was replaced by GM 6258154 sometime between jan. 1976 and Dec. 1981. I once has a pair of 6258154 mounts and they looked very similar.
Attached is a photo of the mount as well as the instruction sheet and list of applications. Note that the Corvette models are not on the list.
BTW, I sent you a PM.
Dave

Dave------


Yes, the 3990916 was also used on other Chevrolet models with big block; it was not unique to Corvettes. The 3990914 was used for most other Chevrolet models with V-8.

The 3886466 was the non-locking style mount. This particular mount was first used for the 1966 model year and became SERVICE for 1963-65. It replaced earlier non-locking style mounts.

The GM #6258154 (actually the mount is GM #330973) is nearly identical to the GM #3990916 (actual mount GM #3980701). I have NOS examples of both. The only difference I have been able to discern is that the spacers welded to the frame of the mount are different. The 3980701 has spacers which are cast and are spot welded to the frame. The 330973 has spacers which are formed of steel stock and arc welded to the frame.