[bnoon]

I had 2.25 40 series on my '86 305 C10 and those were still rather tame. Duals to the rear though, dumps would have been louder.

I had 2.5 40 series on my old '86 Trans Am and those were loud, but echoed a bit due to being a hatchback.

I'm going to swap out my 2.5 glasspacks for 3" 40's on my '76 cammed/headers 454 Sierra. 3" just has a lower tone to it that 2.5 will never have. Since I only drive this when I haul a load or start jones-n for the sound of a cammed big block, the louder and more obnoxious the better!