My 85 12a rx has a Holley 465 from rb. Right now it doesn't really run the best around 1500 rpm to about 3000 rpm I believe it may be a bad fuel and air mixture. I got the fuel pressure set at 5 psi , when I give it gas at 1500 rpm it stutters then it goes away around 3000 rpm. Any pointers that could help me in the right direction would be awesome!