There are many ways to do it. Look up "shock and vibration isolation". The problem is that
industrial stuff is expensive. You should have a sandwich of rubber-like material above and
below the tang sticking out from the engine. The cover, which may be a large washer, should be
cinched down against a hard sleeve, for example, so that the bolt can be tightened. [This is how a typical Ford motor mount works.] If a bolt is left loose in such an application, it will soon fall off. A small piece of channel steel that fits over the top of the rubber and rests on the frame can also be snugged down hard. The later-style engine mount seemed to work, so you can
use its proportions.

Where Are You From? MN

Do You own a car built by Durant? Yes