Z28 motormount?

[68z302]

The 302 in my Camaro had the interlock motormounts on the block when I pulled the engine. I believe these were replacements after a factory recall?
In the trunk was another used motormount (only 1 [img]/ubbthreads/images/graemlins/frown.gif[/img]). It was quite large and not the interlock style.
I have a set of early Camaro small block engine mounts without interlock but they are much smaller than this one.
I'm thinking that it may be one of the original ones.
There is a GM part number on it & was wondering if someone with a parts book would look it up.
The number on the mount is 38864661 with another number right beside that of 1-14 (date?)
Thanks for any help! [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img]
Rob [img]/ubbthreads/images/graemlins/beers.gif[/img]

[William]

Motor mounts and the motor mount frame brackets are a confusing issue.

For '67-'68 all sb and bb used the non-interlock motor mount. This mount uses specific frame bracketry for each application; sb and bb brackets are different.

This changed for '69 when Chevy introduced the new interlocking motor mount for the 302, 350 and all bb. This new mount required different frame brackets than the '67-'68 non-interlock mount. The new mount is narrower and taller than the '67-'68 mount. It won't fit a '67-'68 bracket.

This is where the confusion begins - Chevy continued to use the '67-'68 non-interlock mount and brackets for the 307 and 327. So a '69 307 Camaro used completely different engine mounting components than a '69 SS or Z/28. And unfortunately the non-interlock mount will fit the '69 style frame bracket. It will be a sloppy fit; the engine will be positioned too low and clutch chatter and vibration can result.

Adding to the confusion is the availability of an aftermarket interlock mount for the '67-'68 bracket.

The motor mount should be a tight fit on the frame bracket. If there is a 1/4" or so gap you have the wrong mount for the bracket.

[68z302]

I never had a problem with clutch chatter or vibration so I assumed these mounts were GM replacements for the originals.
If they are replacements would a dealer have changed the frame mounts also? [img]/ubbthreads/images/graemlins/shocked.gif[/img]
I would imagine that before the engine tiedown cables & brackets were added to the Camaros & with hard driving you would tear up a few non interlock mounts pertty easliy.
Like I said I have a pair of non interlock GM mounts from a low mile '68. I thought these mounts would be for any smallblock untill I found the larger mount in the trunk.
By larger I mesn that it has ALOT more rubber to it than the others.
I'll put the 3 different mounts together & compare.
Thanks, [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img]
Rob

[68z302]

OK,
I compared the 3 different mounts, 2 are non interlock.
All three have the same distance from the back plate to centerline of the mounting bolt.
The two flanges dilled for the mount thru bolt are space the same distance apart and all three fit tight on the frame engine mount brackets tightly.
The interlock ones I have must be diffent than the '69 interlock engine mounts. [img]/ubbthreads/images/graemlins/rolleyes.gif[/img]

I'm pretty covinced now that this mount found in my trunk must be an original engine mount for the 302 in '67 & '68.
Can anyone check this number please 38864661 [img]/ubbthreads/images/graemlins/worship.gif[/img]
Thanks as always,
Rob