1973 Grand Prix SJ

here it is, a 1973. the last year for the good ones, it has a pontiac (not super duty)455 with auto, air and every option available that year. it runs, not well. knock or sound of unknown origin. I sold it to a buddy and he is looking to trade it for a dd xj or the likes. Outright money would be 2k i guess. I have put a new oil pump and timing setin it. Runs hei ignition and has no converter from the factory. Limited slip rearend works and this car is scary fast. let me know wht you have.