For price and lack of drone, I think the Moroso spiral flow mufflers are pretty good. Look like a glass pack, but have a baffle system in them that looks like a grain auger. I have one on my c-10 with a 307, powerglide, and 4.10 in rear. Flows good, doesn't drone, and best of all: its a different sound. Plus with a $55 price tag, your not out much if you don't like them. The truck came with it on, and I wouldn't have guessed it sounded as good as it did. Here's a link
http://www.jegs.com/p/Moroso/Moroso-...44819/10002/-1.
I also know the delta flow mufflers that flowmaster makes have a little less drone than the standard series, but their still salty.
If you want more classic tone and one that no one will have, I'd go for the "chambered" mufflers that came on 69 z28 camaros and I think the 69 vettes with side pipes. Their basically just swaged sections of pipe. I think they sound mean. Companies like Classic Chambered Exhaust and Stainless works makes them. They are some more value priced options from other companies, but I don't know any names off the top of my name.