if both cam are the same (g5x3), but one is on a 112 and one is on a 114, which is going to make more power? which is going to be faster in the 1/4 assuming equal setups and eveything being equal?

 

If all engine parameters are the same, the 112 will make slightly more power.

 

On stock motor, the PTV will be tighter though. Too tight for street comfort IMO.

 

would it be fine to run ported ls6 heads and a g5x3 112lsa on the street?

 

It would be safer to flycut. The heads would have to be stock valved with stock gaskets. It will fit but PTV will be tight.
By flycutting you're removing the imminent danger, you can then run thinner gaskets for better quench and SCR/DCR and you can also run bigger valves for more flow.