I went ahead and had the heads flow tested (they were stock on the exh side) and then had Gim at C's port them out close to CJ spec. Then I took them back and had them flowed again. Not much of a gain. 2-3 points, not really wortht he trouble or money, but hey, I had to experiment. Aftermarket heads really are the ticket, but at 2-3K per set... yeah I dont think so.