If you check out the shop manual illustration of the front mount, you'll see that it is deceivingly simple but they don't mention that if not installed to the letter, will cause untold grief.
http://rides.webshots.com/photo/2783812490090459121pDxClp(You'll need to click on "Full Size" in the upper right corner to enlarge this picture so you can see the front engine mount)
Note that the rubber insert can be installed upside down which does make a difference and the clearance between the top plate and the box that holds the insert is critical. My reproduction rubber insert was not as thick as the original and without a load, the top 1/8" plate showed adequate clearance from the bottom box. It was only after I installed the mount, installed the engine with the 620 pounds of weight, and cranked the engine, did I note the lack of clearance and the resulting vibration through the frame.
Trust me when I say that it is best to clamp the mount in a vise securely and make sure that you have adequate clearance. Correcting this lack of clearance requires working on your back under the crossmember with the radiator removed, a jack under the engine and was a big PITA.
So, take my word for it....get the insert correctly installed, clamp it in a vise and squeeze it and I'll bet you'll wind up trimming 1/8" off the upper rim of the lower box component. You'll get enough road feedback through a stock steering column without additional vibrations from the engine.
Dave