I would say go with the 7port because you are used to v-specs and 357 novarossi which are smoother powerband engines. The 5port may be to much down low than what your used to. The JP-3 is not a good pipe for the Go engines. For the 7port you will want a 053 or 2047. The Turbo button is a necessity to get the most power out of the engines, there are times I throw the standard button on just to make it easier to drive on small technical tracks.

You will have plenty of power with the Go engines.