what if any performance gains would you get by modifying the stock merc. manifold on a 502 efi? az speed and marine sells a "short runner " manifold which is a stock manifold with machining work done to it ? i already have the az speed and marine "super tune kit" (ecu re-prog. , adj fuel reg, k+n filter, msd ignit.) plan to add rev. marine exhaust and was wondering if this modified manifold would benefit. also was told the ecu would have to be re-programmed slightly by az speed and marine to compliment the change.

unless you're redy to spend some money on heads,cam,and exhaust I seriously doubt you would be thrilled with the results. ASM is a great company with loads of experience. You need to dictate your goals. 1,2,3,4,5,6,7,8,9,10 mph?

Did you see this post?: http://www.offshoreonly.com/forums/s...ght=Boostpower