360 magnum into '66 Valiant

We have a '66 Canadian Valiant that originally had a 273 2 barrel.
Just finishing up a mild 360 magnum and 727 for this car.

We just discovered the passenger 273 side mount doesn't bolt up to the Magnum.
I went to Schumacher who makes a conversion mount but they are out of stock.
Anybody know of other options for the passenger side?
I figured we could fab up something that will work.

Thanks!