holley hell

Mrmopartech is dead on. That power valve is the primary suspect. Float level is next. On a 4160, you've gotta remove the float bowl to set the float level. A new bowl gasket is probably in order. But I'd keep the fuel pressure below 7 pounds! The stock needle and seat might have problems handling much more pressure than that at idle. And like Mrmopartech says, make sure the secondary linkage clears the intake through full travel (WOT). You should be good to go!