Sbm x block

The X block is identical to a factory 340 block in the lifter valley area.
I had zero problem dropping in a set of Crane ultra pro’s in an X block i ran.
Where you run into problems is with R3 59 degree stuff with the head bolt bosses.
Brian at IMM worked with Comp to come up with a fix for that. I forget the part number, but i remember it being a huge help