Re: Motor mount replacement
Please, call me Dave.
Roger, yes, that modification was available. If I remember it correctly, it consists of a section of steel stranded cable and a U bolt setup. It wrapped around the exhaust manifolds, and cross member, in an effort to capture the engine from getting to high in the chassis if/when the mounts broke. They usually got removed in the long run. I remember the new type safety mounts didn't come along until 1975 or so, that bulletin was in 1972.
The modification I am referring to is a new design (back then), that used a steel interface between the two steel plates, chassis and engine, that locked into each other, and if the rubber delaminated, the steel plates kept the mounts from allowing the engine to lift any distance that might cause trouble. These design mounts have become the standard of the industry.
When I do a serious engine in a serious chassis that makes real power, I install a pair of solid engine mounts, but not like most people do. Most would use two engine mounts and a trans mount of steel, but, that causes more possibilities for serious troubles. Chassis flex, engines and transmissions do not like that at all, they tend to crack, come apart, tear themselves out of the chassis.
I use a solid, or even a urethane mount on the driver side of the engine, and the transmission, and a safety type rubber mount on the pass side of the engine. This keeps the driver side, the side that reacts upward from engine torque, down in the chassis, and the pass side is then allowed a bit of movement, with the engine not rising on that pass side, which stops issues/problems form a solid chassis to solid engine mounting. Just enough play, and solid control for the torque side of the enigne and chassis, to not make trouble.