360 motor mount measurments

What you have there isn't really good...
As you have them, they will want to locate the engine too far forward.
The right side you may be able to correct, but the left will never be correct.
The slot location is off, should be much further forward on bracket.
You may be able to correctly drill the right, but without the dogleg on the front side of the left bracket you won't be able to put your holes in the correct location.
Better off scouring CL for the right parts...I just bought them for $25 locally (which proved the "NOS" left mount I bought through Flea-Bay really was the re-pop POS I thought it was).
Did I say I have a NOS left side Bracket for sale? HaHa