I just recently installed my rebuilt engine into my 54 truck and to reinforce Murphy's law....I got it backwards! Not the engine...the front motor mount insert!!!!
The lower portion...1/8" steel box without a top, holds the rubber insert that you can buy from most any of the suppliers. I haven't found anybody that sells the lower box assembly or the steel plate that goes on top. The rubber cushion has 2 bushings.....the larger, longer part of the bushing goes on the TOP. A steel plate sits on top of this rubber bushing and 2 carriage type bolts drop down through the cross member and are secured with a nut and cotter key. The light oil shield sits on top of this assembly and is secured with a couple 3/8" grade 5 bolts with lock nuts that tie the main motor plate to the center bushings that you can also see from the underside of the cross member. This whole assembly can be installed with the engine in place but would be better installed before the harmonic balancer.
NOTE: There are some clearances and torques that must be maintained as noted in the Fred T's link. However, if you don't have the rubber insert oriented properly you'll have a serious vibration. I used a folded cloth pad, 3/4" plywood pad on top of floor jack...loosened rear mounts and headers and could jack the engine up enough to remove the assembly, flip the rubber insert and bolt it all back together. It was not a pleasant task as there wasn't really any totally effective way to block up the engine while I was making the change. Better to note that it CAN BE DONE WRONG and to get it right before you bolt on the balancer and get the engine lowered into place. Hope this helps prevent others from making this mistake.
Dave
