I just designed my box and came and up with 12.37 sq inches of port per cube is that a little low?

What does more sq inches of port per cube do?

I also came up with about 4.03 cubes per sub before displacment I want to do a little larger what does everyone I think?

My dimensions I used are 23width x 34height x 49 length.

they will be in an 05 f150 with two kicker zx1500. 1 amps powering them for now will upgrade power.

I know they give generall recomendations of 3-5 cubes per sub and 12-16 sq inches of port per cube. What is everyone else running?

and what should I tune to? I did 27 hz my amps lowest is 25 hz and the way I understood what fi said was 2 above your amps lowest.

No such thing as sq inches per cube.  

 

It all depends on your propensity to be bothered by port chuffing.  No one can answer what your tolerance is, but it is really easy to model to tell relative how it will be compared to what you've had before.

Have you modeled your enclosure in something like WinISD to see what port velocity you might be getting?