Originally Posted by Warren Nethercote
Flipper,
It looks like there might be room to run across-member under the engine below the motor mounts. The mounts could go to the cross member and the cross member would not put the same twisting loads on the frame rails as direct attachment of the motor mounts.
(Edit next day: Here is a sketch of what I mean: essentially link your fabricated mounts by a piece of RHS. This tube would reduce the torsional loads on the frame rails, and because the loads on the tube would be largely tension (bending too, but mostly tension I suspect) I think you could get away with 1 or 1 1/2 x whatever tubing. Thus, this cross member would not be as robust as the main suspension cross member)