I have spent many $Ks on parts over the past 15 years, and have bought from all the vendors listed above (and more). None have had parts predictably better than the others (except for Steele Rubber).
My over-riding deciding factors are price and availability (and shipping cost).
My preferred vendors at this time are Classic Parts (nee Chevy Duty), Chevs of the 40s, and Jim Carter. American Classic, The Filling Station, LMC, Ecklers, and Brothers are a close second tier, for a variety of reasons, but they are good.
