Good info, MK IV
As Rick stated, the motor mounts are NOT SPF, but rather a choice of the installer. Some choose good, some do not.
My original installer also used standard rubber mounts, and I also experienced rubbing of the RH side pipe against the opening. Also due in part to my many high rpm burnouts
I upgraded to the Olthoff mounts years ago. They fit perfectly, and have held up well through the years since. Highly recommended by me if you are not currently running them on your Windsor SPF build, even if you are not experiencing motor mount issues right now.
Good catch, madmax, but I would not bother with the chains but rather install good high performance mounts that are up to the task
Jim