Wear did you get the extension ,endcap and bumper at.jak_nelson said:tracks usa has good rail extensions. They extend the hyfax, so you will be buying new hyfax. From what I hear their tunnel extensions are good too. I purchased a 2000 summit hymark extension, end cap and bumper. cost about the same. The nice thing about the summit bumper is that it extends to the original tunnel and not just attatched to the extension. As for track, dont know. I have a camo 1.5 lug 136. Works for me.