I am purchasing a 65 Riviera GS and wonder if you guys can help on an engine production code stamping question. Assume it a 425. Most confusing is the L is more than two inches away from the X167. The L is not a clear crisp stamp like the others. It would be helpful if I could include a photo. Also on this 65 are the 2 carbs with a metal sticker on each throat that reads Carter Competition, clearly not original. Look on the side of the carb and raised factory letters read WEBER, so its not an original Carter carb. Does this create concerns. I also need to measure the exhaust pipe dia. to help determine if its was original GS. It does have the Gran Sport emblems in the right ( early production ) location and on the glove box.