If you need parts for your 1960-66 GMC or Chevy, here are a few places to choose from.
GMC Pauls
American Classic Truck Parts
Golden State parts
Brothers
Chevy Duty
LMC Truck
Scotts Super Trucks
Truck Shop
Here are other Cool links.
I am a member of this awsome group. I can truly say if is wasn't for these great people in this group, I would not have my truck right now.  Back when I first got my truck and became a member of this group, I became discouraged and was considering selling my truck.  This group told me what a great truck I had.  So I kept it and WOW I am sure glad I did.  If you have a 1960-66 GMC truck, or a vehicle that is powerd by a GMC 60 degree  V6/V8/V12 built between 1960-1974, I greatly encourage you to join.  You will learn all kinds of things about theses great trucks and engines.
4 Wheel Drive
This is a great site with all kinds of 4X4 information, links, and other cool stuff. If you are into 4X4ing, go check them out!
Exhaust Recordings
Second Page
Home
Links
350 V8
305 V6
New Seats/Mirrors
Exhaust Tips
NP-435 Tranny
King Arthurs Computers
The owner of this web site is the one who greatly helped me with my 350/350 combo swap. He has all kinds of cool pics of his 1962 GMC with a 350 that has 470 horsepower!! As well as pictures of my new 350. Take a look ;)
If you like the sound of exhaust like myself, you should check out ExhaustSoundClips.com 
This website is great. You can listen to many kinds of exhaust systems and as they say it "Hear it before you buy it!" Not just that, if you have an exhaust recording of your own you can submit it and see what kind of feedback or ratings it gets. Isn't that cool?