exhaust manifold/header

[69ChevySB]

Ok im taking off my brand new summit headers I just bought because they are a pain once i tried putting them on and they interfere with my clutch linkage too badly...so i'm putting my exhaust manifolds back on...

Once I get them back on, i'm going to take my truck to the muffler shop and get dual exhaust coming straight out the back. Now, my questions are....

1. ) What size of pipe should I have them use? and what's the difference between the pipe size anyway?
(2", 2 1/4", or 2 1/2")?

2. ) What kind of mufflers should I buy?...I want good performance, and I want a really nice and smooth sound. I don't want anything too loud or fancy that's going to cost me 100-150$ dollars a piece for each muffler.

3. ) Is it better to use welds or clamp ons? What is cheaper? Does anyone know of any sites or companies that sell these clamp on dual exhaust kits for rear exit as I have described?

My truck is a 69 shortbed with 327 block/350 heads and a standard 3 speed on the floor


Please give me suggestions on what would be my best way to approach this for my daily driver with that current setup. I don't really know too much about the different kinds of pipe sizes and mufflers so I need advice. Thanks a ton.