I have several pump gas street stroker motors, one is a 518 low deck with 10.29 to 1 compression and the other one is a 464 C.I. 440 motor(3.9 stroke with 4.50 bore) Both motors have Eddy RPM heads. The big motor has a set of the CNC ported Eddy RPM by MCH and the little motor has a stock set of Eddy RPM, the big motor has a Comp Cams solid roller that is 260@ .050 intake and 266 @ .050 exhaust, both have over .700 net lift at the retainers. The little motor has a Comp Cams XE295HL cam and lifters, that motor has 10.46 to 1 comp, ratio. Both motors run well on the local pump swill with the total timing set at 34 to 37 degrees, depending on the track altitude and weather Don't forget that big C.I. motors eat big duration cams and need big air into and out of them