OK here's the gist of it. I own a 93' K5 Blazer with a built 350 SB in it. 204/214 cam, roller rockers, full MSD ignition system, Custom Injectors, TBI Spacer, Custom chip, and hooker headers to flow master exhaust. I need more back pressure though to help with the "rich" issue I have now. Exhaust flow is to fast to get a good read even with the sensor mounted in an elbow off the header. So what I'm wondering is can I add on a set of ST's and tune them to get the flow right? Current tips are coated in soot. Or should I dump the flow masters and then put on the ST's? Truck sucks out off the hole right now but pulls very hard when getting on it at highway speeds. I want the hole shot power back for those days when I'm out in the woods.

thanks for any advice or help,