I am putting 2 RL-P 12's in a ported box of 3 ft^3 net tuned to 34Hz. Can you check my port size to make sure I am good to go?

I come up with 3"x16" for 48 square inches at 29.6" long. Gives me a vent mach of .07 which seems sufficient.

Or I could go 2.5"x16" for 40 square inches and only 23.7" long with a mach of .08.

Do you think either will be the same as far as keeping port noise down? This will be in a trunk too.