I know that the topic of motor mounts has come up numerous times in here. However, I wanted to share some information with everyone.
I am running a 351W in an A&C Cobra and I have been using stock replacement stamped mounts that I got from Autozone. I am not too hard on the accelerator and now the car has a little over 3,500 miles on it. Yesterday, I had the car up on a jack to drain the
oil and I noticed that one of the motor mounts seemed to have a split in the rubber. On closer inspection, it was clear that the rubber had started to split. This was only on one of the mounts, apparently the torque side of the engine.
I just ordered Prothane mounts from Summit. A little pricey at $96.00 but I'm sure they will be far superior to the over the counter stock replacements. I had checked with Energy Suspension and they advised that they don't make a mount that I could use without modifying the chassis bracket where the mount attaches to. The prothane mounts are made with a protective plate to prevent the mount from separating.
If you are interested in the Prothane mounts, the Summit number is PTP-6-503
The main thrust of this post is not to just share what happened to me, but more so to pass along some important advice. How often do we even look at or check our motor mounts? Probably hardly at all. I think it's a good idea to get under your cars and inspect your mounts periodically, especially if you are using the stamped stock replacement mounts.
Tony
P.S. If you don't want to invest in the better mounts you can always drill through the stock mounts and insert a bolt/washer/nut setup to prevent the mount from separating under high torque situations; or you can fabricate torque limiting straps beteween the engine and the frame.