Muffler Question

[78 Chevyrado]

I'm pretty sure I'm going to get a new muffler pretty soon. I have a 2.5" single pipe from the y-pipe to the tip out back. Right now I have a dynomax 2.5" in/out turbo.

I'm going to get one of those cherry bomb vortex mufflers on it. My question is, should I just get the 2.5" in/out muffler or should I get a 3" in/out on my 2.5" pipes.

Would that make a difference in the sound? I'm not getting a 3" tailpipe, it'll stay at 2.5" either way. The 3" and the 2.5" vortex mufflers both cost the same and have the same outer case dimensions.

I have heard of mufflers for a 2.5 system actually having less than 2.5" internals. I'm pretty sure either one would work good, but I'd like which ever would be deeper sounding, if it would make a difference at all.

Thanks Guys