Engine Mount Question, to change or not to change

[Bert W]

Where I come from they are called motor mounts. Anyway, my engine is almost finished at the machine shop. I have read through Roj2323 mount swap. Here for ref:

http://67-72chevytrucks.com/vboard/s...d.php?t=128765

The block I am using is an 86 model. Should I do this conversion or just use the standard setup that was on my 307, new of course? The engine is not much more than stock, small cam, headers, 4bbl, etc. Thanks for any enlightenment you may have on the subject.

[AusTx68]

Why would you considering using the 73-87 mounts? Is there something you like about them? I say stick with what you have or go to a tubular aftermarket set. They will bolt right in.

[cdowns]

the originals lasted 40 years

[WAAF]

isn't the 73 up interlocking type..
a failed motor mount can hang the throttle open..
if a lead foot, thats reason enough

[Bert W]

Thanks for the input fellas!

[mcbassin]

Bert,
I used the 73 up style with clamshells for my build. The main reason, I have had a few of the oem style fail in my big block truck. You can add chains or cables to keep if from over traveling in the event of an over torque situation. I prefer these style mounts. Just my 2 cents. I had to drill a few hole to use them. But I am also using an LS engine in my build.

[hjewell2]

Originally Posted by cdowns

the originals lasted 40 years

Right there is reason enough to change them. 40YRS old biscuit style mounts.

[MARKDTN]

I would swap. There is definitely a reason that GM went to interlocking mounts. On my '64 Impala I broke a mount which put the fan into the shroud which bent both. If I hadn't had a steel shroud, it would have gone through the hood or at least dented it. If I hadn't been at a low speed it probably would have gotten the radiator too.

[mcbassin]

Originally Posted by MARKDTN

I would swap. There is definitely a reason that GM went to interlocking mounts. On my '64 Impala I broke a mount which put the fan into the shroud which bent both. If I hadn't had a steel shroud, it would have gone through the hood or at least dented it. If I hadn't been at a low speed it probably would have gotten the radiator too.

I forgot about my buddy's truck that shelled his radiator when his broke. He had the old school flex fan that chewed the crap out of the fins on the radiator when he launched and the mount gave. wasn't pretty.
40 year technology isn't always the best.

[haminator]

The originals really are'nt that good but I myself can't bring myself to switch. I still insist on running the drivers side alt. too. I'm kinda weird that way. I wouln't even go to HEI until about 1995.

[MARKDTN]

Originally Posted by haminator

The originals really are'nt that good but I myself can't bring myself to switch. I still insist on running the drivers side alt. too. I'm kinda weird that way. I wouln't even go to HEI until about 1995.

I'm not sure I would go out of my way to change them on a driving vehicle, but if I already had the engine out it would be a good time.

[ChevLoRay]

If you wanna use OEM type, then you might want to scrounge up one of the restraints that GM installed as a result of the recall notice when the motor mounts started coming apart. Here's a pic of the loop that mounts to the chassis. Then, you need to fabricate a duplicate of the cable that went through the loop and around the exhaust manifold. If you run OEM manifolds and have OEM motor mounts, the cable and loop will lend an air or authenticity that all is as GM intended for it to be.

[haminator]

I have only seen one truck with those cables still on it. What years were recalled? Wonder if they'de still honor that recall? lol.

[oldgold70c10]

Get the poly mounts from Summit. They have an internal locking feature if they do break.

[haminator]

Great idea.