[DanEC]

By the way - if you trim the engine header pipes to move the collector and headpipe in a 1/2 inch, you will also raise the level of the headpipe by 1/2 inch since the exhaust come off the engine at about a 45 deg angle.

Have you checked to make sure the engine is dead level in the chassis? If it's rotated even slightly, that gets magnified way out there at the end of the exhaust head pipe.