ORIGINAL: bobkra
The stand offs that come with the DL50 have a slight heat warp on the side that mounts against the firewall.
Are you sure that's the side that is supposed to mount against the firewall?
I took a good look at the mount and the froces involved and believe it's much better to use it so that the four "legs" bolt onto the firewall and the flat strip goes against the motor.
This provides vastly increased protection against the lugs breaking (since there's now a beam between them) and also means that you're more likely to get a firewall fracture than a lug-break in the event of a prop-strike or other impact.
That's the way I've installed mine, I'll include pictures later.