Original long bolts for 1969 L/78 motor mounts

[rszmjt]

paceme,

Thanks for posting, your mounts look the same as my original Z28 mounts, except mine have RBW bolts.

 I am still puzzled by the AIM  (Z28 page) and bracket shown on page 1 of this post.  The mount appears to be different, unless it is just a generic drawing, it also shows the bolt going in from the front.

[JohnZ]

paceme,

Thanks for posting, your mounts look the same as my original Z28 mounts, except mine have RBW bolts.

 I am still puzzled by the AIM  (Z28 page) and bracket shown on page 1 of this post.  The mount appears to be different, unless it is just a generic drawing, it also shows the bolt going in from the front.

If you look closely at all the engine mount illustrations and pay attention to the change dates in the title block, you'll see that ALL the engine-side mounts for L-34/35, L-48, L-78, and Z/28 were changed between 5/29/69 and 6/2/69, and the base V-8 mounts were changed on 8/6/69. Cars built before that ALL had different old-style mounts.

[rszmjt]

paceme,

Thanks for posting, your mounts look the same as my original Z28 mounts, except mine have RBW bolts.

 I am still puzzled by the AIM  (Z28 page) and bracket shown on page 1 of this post.  The mount appears to be different, unless it is just a generic drawing, it also shows the bolt going in from the front.

If you look closely at all the engine mount illustrations and pay attention to the change dates in the title block, you'll see that ALL the engine-side mounts for L-34/35, L-48, L-78, and Z/28 were changed between 5/29/69 and 6/2/69, and the base V-8 mounts were changed on 8/6/69. Cars built before that ALL had different old-style mounts.

Thanks John, So if I am understanding correctly the mounts shown that I posted were used until 6/2/69? ( June?)

[rszmjt]

paceme,

Thanks for posting, your mounts look the same as my original Z28 mounts, except mine have RBW bolts.

 I am still puzzled by the AIM  (Z28 page) and bracket shown on page 1 of this post.  The mount appears to be different, unless it is just a generic drawing, it also shows the bolt going in from the front.

Never Mind, I answered my own question tonite. I was looking in my own AIM and mine shows the bolt going from the back on the drivers side mount, there is a revision on my page.

[firstgenaddict]

Thanks Shaugs... that is exactly what I was looking for!
Now is anyone reproducing the correct EARLY style 69 HP mount?

[rszmjt]

Is the mount that uses these brackets shorter than a regular mount to allow for the thickness of the bracket , or does the engine set higher ? How thick is the bracket ?

The Z28 frame brackets are different heights to compensate for the additional thickness of the antilift bracket, their difference is exactly the thickness of the bracket. Here are some shots of my Z28 mounts with a Heartbeat Repo antilift bracket. Hope this helps.

[mark x22]

Thanks . does any one know if on a big block if the rubber mount is thinner with the bracket ?

[rszmjt]

Thanks . does any one know if on a big block if the rubber mount is thinner with the bracket ?

I think Steve shows that the 396 RH frame mount is taller on page 1 of this post, I think all the engine insulators are the same physical height, the anti lift bracket thickness is equalized by the frame mounts.

[mark x22]

The big block frame stands are different to offset the engine to the right . I was wanting to know if the rubber mount was different on the left to allow for the anti lift bracket thickness .

[rszmjt]

The big block frame stands are different to offset the engine to the right . I was wanting to know if the rubber mount was different on the left to allow for the anti lift bracket thickness .

Not sure on the big block mount but the small block rubber mounts I posted pictures of, are the same hite.

[firstgenaddict]

"The Z28 frame brackets are different heights to compensate for the additional thickness of the antilift bracket, their difference is exactly the thickness of the bracket."

Here is my opinion on the frame stand height difference...

This, I believe, is merely a coincidence, as the retrofit was more than 2/3 of the way through 1969 production.

Why, if the safety stop was taken into consideration when the frame stands were designed, were they not installed until after 9-10 months of production? 

[rszmjt]

"The Z28 frame brackets are different heights to compensate for the additional thickness of the antilift bracket, their difference is exactly the thickness of the bracket."

Here is my opinion on the frame stand height difference...

This, I believe, is merely a coincidence, as the retrofit was more than 2/3 of the way through 1969 production.

Why, if the safety stop was taken into consideration when the frame stands were designed, were they not installed until after 9-10 months of production? 

Hi James,

You might very well be correct, never thought about it that way. I have changed lots of engines in first gens in the last 40 years and I have never had trouble getting the engine to sit level, but I guess that is why both engine frame stands are slotted. I probably just assumed the hite difference was because of the antilift bracket, mainly because of this post. I ran a Corvette/Camaro restoration shop for 18 years (1987-2005) and I have only seen these anti lift brackets a few times, last 1 was in a 69 Corvette 350/300hp car.
 It would be interesting to know how many cars originally had them, I wonder if lots of them were removed under the engine mount recall program.
 The mystery continues.

[rsr]

Have these long bolts and spacers along with correct engine mounts been reproduced by anybody yet?

[blackss69]

As far as I know the motor mounts are not reproduced.  Originals are very $$$$.  I have original motor mounts in good condition.   

I have a 69 396/375 and I purchased the support from HBC.  For the bolts, washers, spacer you can look in the AIM for part numbers and then in the AMK Products catalog and cross reference GM numbers to AMK hardware.  You can find most of the hardware.  I think the long bolt was listed as a Pontiac part.  For the bushing I cut down the length of a generator spacer with the correct ID and OD.  You can get a good idea of lengths, etc. by looking at the photographs.  The hardware was placed on marked background.  I hope this helps.