Clifford Intake and ? headers

Those look like garden variety Hooker/Hedmann/Blackjack/Cyclone headers (Cliffords have shorter primaries?). Not a bad thing, they'll do the trick. That shiny black paint will last about 3 minutes though.

So, you can either run duals, or 2" collectors Y-branching into a 2 1/2" single system. I'd suggest the big single.