327 Motor Mounts

[sodly]

I understand that GM had a problem with the 327 (C-20) motor mounts on the 1966 pickups and there was even a recall on them. My truck seems to be one of these since it has (what I assume are dealer-installed) torque straps/cables wrapped around each motor mount and the block.

My question is what are people using to replace their original 327 motor mounts? Is there a newer, upgraded version that is more reliable than what the truck came with in '66? In some of the catalogs I see two different versions listed-- one normal and one "urethane... designed with an interlocking in case of a failure." Can anyone explain this? Also, same question for the transmission mounts. Mine has the TH400. Is there a superior version of these or are they all basically the same? I'm going for a stock look but if performance is that much different it might be worth putting in the better mounts regardless of their appearance. I'm perplexed. Thanks!

[aerotruk63]

The old style mounts could pull apart but the newer style has a retainer as to not allow the motor to twist over. Personally I like the idea of the torque straps.

[66 C10 383]

A lot of people don't remember the feeling of the *thump* when a motor mount separated in 2. Even with the recall torque straps, as the engine would torque over you could feel it when the power was reduced and the engine would land back down on the mount. Guess I'm giving hints to my age ...

The torque straps were part of a recall used on engines with the older style mounts. The mounts were redesigned with the interlock built in and that is (as far as I know) all that are available, either in rubber or poly.

I believe the trans mounts are the same way. I remember guys who use to run a hose clamp around the trans mount to keep it from separating.

Rubber mounts will soften the engine vibrations from the frame but also allow more drivetrain movement. Poly mounts will hold things more stable but also reduce the movement from the engines torque.

If you want to look stock and run poly too, just get them in black and most people won't even be able to tell the difference.

[sodly]

Thanks everyone. Can anyone show me pics illustrating the difference between new/old and rubber/poly?

[60-66]

3894219 is the original GM part number. This was superceded in 1972 by 3990332 which is the inter locking type.

[padresag]

and the insulators were more prone to break behind an a/trans than a standard.
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