I have a 4779 in the parts tank now. Factory 73 jets in it, power valve in the primary side only. I am jetting it up to 75 and 85. I am not liking having just the power valve on one side so will probably sell it or trade for a different model. You have to understand that just because you are giving the car more fuel, it doesn't necessarily mean your motor is able to handle it. Timing, compression, spark plugs, ignition, etc ... have very large roles to play in burning all that extra fuel and putting it's power to the wheels. Just dumping more fuel doesn't automatically mean more power.