I was going to drill 2 holes thru it and put about 2-3 rectangles of it sideways (for rear mount). and have the half-pipe looking mount behind it to hold the frame..
But i found a welder that has a bunch of solid steel that he'll sell me for cheap sooo solid is way better for mounting hardware right??? right..i think
Inner tube, garden hose, pantie hose, doesn't make any difference. If it is resilient you don't want it in your engine mounts. The engine needs to be mounted solid, metal to metal in your frame.
You can't eliminate vibrations by putting rubber in the mounts.
Try it if you want but all experienced builders will tell you the same thing because most have tried it and found it didn't work but actually increased vibrations and caused other problems. As said above, there are numerous pages of discussion on "rubber mounting" here to read.
Tom