I have found the overall offering for parts for the '60-'66 Chevy/GMC trucks, Panels & Suburbans, is larger from Truck and Car Shop, than either LMC Truck or Classic Parts.
My shop is close to LMC Truck, Classic Parts & Jim Carter, all of which offer many of the same parts, but some prices are better from LMC Truck and some prices are better from Classic Parts. Some parts are better quality from LMC Truck and some parts are better quality from Classic Parts.
I have found the quality, fit, finish, price & variety of parts, vary from supplier-to-supplier. I wouldn't say the quality of the part is better, simply because it cost a bit more. In some cases, I am really surprised that the suppliers don't do a better job of scouting the competition, in order to determine price-points.
Being so close to a parts supplier, is quite an advantage, because I can inspect the parts, prior to purchasing them, which is much better than waiting to see what I get after the parts arrive in the mail. If the quality, fit & finish is sub-par, I have already paid for the item, including tax & shipping and often times, it is not worth the hassle, time or money to package it and send it back for a refund. For this reason, I make every effort to buy locally, but I have found the Truck and Car Shop to be very competitive on price, quality, fit & finish, compared to the many other suppliers, I have tried.
Here is a list of other vendors, that supply parts for the '60-'66 Chevy/GMC trucks, Panels & Suburbans:
www.bowtiebits.comwww.lmctruck.comwww.classicparts.comwww.oldchevytrucks.comwww.ecklerstrucks.comwww.gspp.comwww.truckandcarshop.comwww.harmons.comwww.oldmusclecars.comwww.classicchevroletparts.comwww.classicindustries.comwww.bobschevytrucks.comwww.brotherstrucks.comwww.mar-k.comwww.wheelvintiques.comwww.totallystainless.comwww.earlyclassic.comwww.horkeyswoodandparts.comwww.raybuck.comwww.americanclassic.comwww.yogisinc.comwww.rbsauto.comwww.obschevy.comwww.cheyennepickup.comwww.chevypickupparts.comwww.fillingstation.comAlthough the number of parts and variety varies greatly, all of these supplies offer something for the '60-'66 Chevy/GMC trucks, Panels & Suburbans and most of them offer a free catalog.