Mufflers: Offset vs. center outlet

I doubt there is any sound difference, I think it's for placement more than anything else.

agreed, no sound difference, inlet and outlet configuration only affects fitment. Early models normally use offset inlet and center outlet.

May I suggest the Hooker Aerochamber? They have a nice rumbly idle and cruise, fairly quiet while at the same being heard, and when you're hard on the throttle they really rip. On my 65 F100, I ran dual 2 1/2" pipes into a single 3" outlet aerochamber, sounds absolutely perfect.

Placement is the only reason....

Ill throw in my 2 cents and say go for Magnaflows....

you get the straight through design for the extra power and our quiet while cruising around...I can talk on my cell phone when cruising but when I put my foot into it it sounds beautiful

I'll put in my vote for anything made by Walker / Tenneco, who make the dynomax line.
Fit / finish is always good, and the performance and sound is excellent.

However, asking about mufflers is a very opinionated thing, about like asking about which oil you like to use.... lots of judgement calls.

For example when flomasters first came out, a lot of guys had to have them, I for one have never liked the sound of them. This is one huge advantage of being in a car club, chances are you can hear a lot of different combinations by walking around the parking lot.