I'm running a 65 with 450 hp small block. Currently solid mounts. I want to go rubber to eliminate some vibrations. I don't race the car but do stomp it down quite often LOL. What's chances of breaking a mount? I'm not sure which is the better choice. I don't want to twist anything with the solid mounts either.

This issue came up in a thread about engine to hood clearance. It was mentioned bracing the engine to the frame to eliminate excess movement from torque. I currently have the block literally chained to the frame. It works well, but definetly adds some harshness that you are probably wanting to get away from. Instead of going to just rubber, have you considered poly?
Also, I have thought about using a turnbuckle and rod-end setup but don't have a local source to piece it together and I have yet to find a pre-packaged solution on the market.

thanks for the info I guess I'll look into the poly bushings. My hood clearance is close right now.
http://s607.photobucket.com/albums/tt155/malibu4720/th_100_0360.jpg

Just pop a rubber mount on the passenger side, keep the solid on the driver's side - that's they way I have it set up, and several others on this site. No noticeable vibration.

Check this out: I took PDQ's advice, bought the cheap 327 mounts, and put two bolts through the "sandwich" part of the mount. I had to turn the heads of the bolts down to about 1/8 inch for clearance to the frame stands, but with a 3/8 bolt, it's still strong enough.

I also welded the two spots where the interlocking lower parts meet. The cheap mounts are about $7 each, and the whole modifying job took about an hour.

Chevy's solution to breaking motor mounts back in the day was a 3/16 steel cable wrapped around the a-arm dog bone and bolted to an exhaust bolt........Got one in the garage somewhere from a 65 wagon.......

Steve O.

thanks guys for all the help. swappin out one mount seems the simplest way to go/