I had to use Micro-Mark Kadee spacers to lower the couplers on these cars that I had converted to 2-rail as the couplers seemed a bit higher, when tested with the Kadee Height Gauge.
Also, using the spacer, also reduces the length of the screws (securing the Kadee coupler-box to the body of the car) that intrudes into the floor of the car but doesn’t completely prevent it. The screws that were shipped loose, with these cars, were slightly longer than 3/8” & that wouldn’t have solved this issue either.
Naveen, I've run into the "finding-the-right screw-length issue" several times in the past when working with Kadee coupler boxes and shims.
In cases where the screw is just slightly too long (and the next shorter-length screw is too short!), I've added a tiny washer (or two) under the screw head--between it and the coupler box.
This serves to shorten the screw just enough to prevent it from protruding through the floor...or end platform on cabooses and engines.
I purchase the tiny washers from Micro Fasteners and keep a supply of various sizes (i.e. 2-56, 4-40, etc.) on hand at all times.