Seems like you have done the major stuff and nice componants. What gear are you running and have you installed a MSD type system for your ignition? Also look at the whole exhaust system 2 1/2" to 3" with headers. Also tail tips that look factory but have the 2 1/2" to 3" opening. Fuel line 5/16? You need 3/8". Your Challenger was a small block so it came with the 5/16" line. Also need the 3/8" pick up. All these can be found on E-Bay Motors. Heads are where its at and the 906s are a good factory head. But they need work to make big #s. Also did you upgrade the springs in the head when you put in the 509? There are some really free flowing heads done in aluminium by just about everyone. Spark plug wires and plugs are also a good upgrade as well as a real cool motor. Aluminium radiators are a good inveatment as well as a 170 thermostat. I hope this helps.
