I have a 460, Weiand Stealth intake, with an 850 built by Pro-Systems, 4 corner idle and I have a wide band to monitor A/F ratios. Not sure what is ideal ratio, but it idles great at about 13.5-13,9. So I take it for a drive on the street for about 20 minutes, idle quality goes downhill. I notice A/F ratio now up 18-20. I guess I should be looking for vacuum leaks around intake, carb, etc. Any ideas as to why its leaning out idling while hot?