Also, International Rails come in different sizes. Some American made chassis are 1-1/8" rail and some are 1-1/4" rail.  Some European made chassis are 28mm, 30mm or 32mm.  Not all International Rail engine mounts will fit all rail sizes.  Some will fit 1-1/8" and 30mm, but not 1-1/4" and 32mm (and vice versa).  As a rule, Burris brand engine mounts are machined to fit all sizes of International rails.  You can measure the size of your rails with a dial caliper to make sure what you have.  Many newer American made chassis that claim to be 1.25" rail actually are 1-1/4" rail for some but not all of the chassis.  Check your engine mount frame rails to be sure before ordering an engine mount.