Sorry... I like that the aftermarket mounts have a nice feature built in like this. Shoulda been that way from the factory. I don't know exactly how the physics work... it's too much for my little brain, but I have seen a guy break a passenger side mount from doing goofy things with his car in reverse. It was in high school... what do you expect. He would drop his car in reverse, do a power brake, and the engine would raise up and the fan would start chewing on the fan shroud.
I had a 4 spd 68 cougar in high school.I used to amaze my freinds with the ability to stand in one spot and smoke the hides...2 feet...3 pedals...K code 289 and a posi...oh what fun high school was!!! Had a freind do that reverse drop thing once in his chevelle.Mounts stayed together...trans was on the pavement in little pieces...That was soo funny to see... As for the physics of how it works...engine rotation my freind,all that reciprocating mass builds lots of energy...it dont all go to the rear axle...unfortunately...
I got a mount tonight from auto zone. It didn't have the bolt through it. I thought they all did. It's replacing one that was on the passenger side. But I'm going to put it on the driver's side Since I've got a torque strap also on that side
My (new) mounts didn't have the bolts. It sounds like it would have been easier to make the mounts "solid" for drag race applications. Here's a thread on the subject: http://mmb.maverick.to/showthread.php?t=28379&highlight=solid&page=5 Glad you made it through your ordeal without selling your car!
I drilled a 2 holes in the mount and used flat head cap screws to pin the rubber to the metal. It's not a harsh as a solid mount but almost as strong. This can be done with the Maverick mount also. See http://1bad6t.com/motormounts.html
Good pics. Mine were similar and I found they worked great. Stiff but driveable. Still gives some cushion for vibration.