That's some time and stone shaping to fix that.
I wonder what the seat widths are. Any room there to keep the seat touch to a minimum in other words.
About a 1 11/16 or 1 7/8 30*/15* with softened/rounded off edge to dig the exh out after the 45 is touched and maybe see if you can narrow it just a smidge for the lower angle. Intake same deal. When theres that much chamber.. it's just more work in most cases. Then again..I guess it all depends on how carried away you wanna get.