Guys.......I am running a 67 440 HP that is .060 over in my 67 GTX. The only modifcations to the engine are a 6-pack cam and a good valve job on stock heads. It has the stock 4327s Carter AFB. The jetting is stock: primaries @ .098 and secondaries @ .077 I'm running stock 3:23 gears and a 727 auto transmission. Does anyone know how big I can goto on the secondary jets for more top end power without affecting basic drivabilty ?