HOn3 3' 7 Arch Bar HGC Trucks (3 ft 7 in) HGC Two Piece Fully Equalized Trucks These HOn3 trucks use the same two piece design and material as our HO scale HGC trucks. HGC means High Gravity Compound which is a high tech plastic/metal composite material. These are simple and easy to assemble and install. Once installed properly they will have a free rolling, flexible, equalizing ride similar to our #716 and #717 HOn3 fully sprung truck kits. Included are center bushing adapters for attaching the trucks to various makes of cars such as Blackstone and Micro-Trains. These trucks require a flat mounting surface and some models may require trimming and filing of the car's bolster to make a flat surface. The bushings are designed for the original screws or where appropriate 0-48 self-tapping, 0-80 machine screws, or 1mm to 1.25mm metric equivalent. Prior to assembly please review the photos and drawings and read the instructions. Determine which bushing adapter you will need for your particular model or if you need to modify the bolster of the car to properly install the trucks. To Assemble: Take two side frames and fit them together at the center, hold at the center connection (inverted or bottom up) and set one wheelset into one end then turn the truck around and hold it by the side frames and fit the second wheelset into the side frames. Be careful not to force the axle tips into the frame as it may damage the tips. Holding the truck by the sides, keeping the wheelsets in place, insert the bushing of your choice from the bottom and make sure it's properly seated. You can now either attach it to the car or set it down inverted on a flat surface to wait for installation. The truck will hold together inverted but if you need to store the assembled trucks for any length of time prior to installation we recommend putting a screw through the bushing with a hex nut on the other end or something to securely keep the bushing in