Alex, you will need six of these. Use a local welder.
Cheaper than IMS.

I have the welding cups for the mm rubber bushings already.
Here is a pic of the box full :)

If you make up about 2 dozen we can sell them to others
for their motor mounts. Cheaper by the dozen :)

The tube is 1.25" OD .065" wall 4.5" long 4130. Welds well to 321 SS.
Use a 3/8 bolt to bolt it to the composite firewall.

Paul Lamar