Hi, I got a 67 Riviera with a stock 430. I has about 180.000 miles on it and it runs really quiet and nice. I have 10 degrees advanced timing at idle, I have a total timing of 32 degrees and a adjustable vacuum unit. The car has an aftermarked HEI-distributor (dragonfire). The car runs really nice, quiet and great, but my idle is not the best. However when you look at the engine it really looks free of vibrations, both in Park and drive at idle. The carb has been rebuilt and i got about 20 hg vacuum at idle (650 rpm). But, the exhaust smell and sound is not very nice at idle. Is it possible that 10 degrees advance at idle can be to much for a stock 430? I got to have 10 degrees to get 32 degrees total advance, but if the idle could be better with less idle advance, I will do that. Any opinions? Regards, from Norway.