Trials & Tribulations of the Empire State Express

In late October 2011 after receiving numerous complaints from crews and passengers the 8 car set of IHC 86' corrugated side passenger cars lettered for the Empire State Express were removed from service. All 8 cars were suffering from excessive rocking at both low and high speeds.
The cars were forwarded to the Terminal Repair Shop where skilled craftsmen diagnosed the problem(s) and came up with a cost effective plan of action for rebuilding the cars. Here is a list of steps taken to correct the erratic and annoying behavior of these cars;
Completely disassembled cars.
Added steel weights to floors. NMRA weight standard for this sized car is 7 ounces.
Discarded plastic wheel sets.
Reworked trucks to accept 33" metal wheels. (Proto 2000 and Kadee)
Tested trucks to ensure all were free rolling with no wobbling.
Removed nub on top of trucks that rested against bolster.
Drilled out bolsters to accept #6 machine screws.
Discarded plastic press pins that attached trucks to bodies.
Attached trucks with #6 screws using flat washers on both the bottom and top of the trucks. This step is very important as the lower washers add stability and the top washer allows room for the McHenry couplers to swing freely without getting caught up on the car diaphragms.After tightening assembly with #4 nut and allowing a bit of free play I added locked the nut and bolt together with CA. 
Road tested on through Atlas #6 turnouts and 22" and 24" radius curves. Cars ride steady and no derailments have been reported.
Empire State Express put back into service.