unless you are stuck on an inline head (and assuming you want to keep your headers), i would run a 185cc total engine airflow TFS TW for a number of reasons if it were mine. I would mill them down to about 54cc chambers, change the cam (afm n41 would run pretty well in this combo for an ots deal, id start with the intake at 110ish), port the intake and put at least a 4.10 in it.