2.65" ID or 3.76" ID packed column

[spencer321]

i have 2 choices for pipe on my next build, stainless (sorry i don't do copper i work with master tig welders) 2.5 sch 10 is 2.65 inside with 1/8th inch wall or 3.5 sch 10 3.76" inside 1/8th inch wall. Currently i have 1.75 with approx 1/4 inch wall (way overkill but it was free) i enjoy my product it just takes too long with a smaller diameter. I've read the huge jump from 2 to 3 inch which is why i question if 2.65 is enough, but i've also read 4" is too big for a keg, this is 3.76" so a touch smaller.

anyone with a suggestion? price is actually really close on the pipe and fittings so thats not a concern