Sorry been away for a while but you've been in good hands with Pat and Jim's support.
Actually no dreaming-been very happy it ain't me on my back (again) upside down.
I'm not nuts about 1/2" but any more and I'd be up nights...
If more, you could have Nick cut you a shim to the Melling bolt pattern.
The real PIA for you is that Shelbys have the crossmember that ERA's do not. Wide open under our pans. Try not to lift the motor. On top of the extra work and contact points the boys mentioned you don't wanna drill/bash/push against a dangling 600 pounds of crap. Unless you shim the space on the mounts temporarily.
A few sips of Macallan 21 yr old would be nice...Then NONE of us would care about
oil leaks