Haven't seen the original poster on this thread in some time... But if he comes back, some of the best money I've spent on my coach is the addition of an AFM.
Thanks for all that! I assume you mean air/fuel meter? Monitoring 2 gases or 4?
I've spent a lot of time with those struggling to get vehicles through emission.
What kind of numbers are you running? Can't say it's been my main diagnostic tool, though it's fairly easy to set a carb where the HCs are to high most of the time. Mine has FI which controls the mixture. Worth checking at some point though.
BTW, does your Howell system control timing for you? FiTech also has that now. Mine does not, though.
After a couple of years, my rig is usable and I know my engine and transmission are solid. This is my first big block engine and I'm finally at the point where I can start tweaking various tuneup parameters to increase power and mileage (Recurve of the distributor is a strong possibility, though I'll need to set up a timing monitor setup to really see what's going on. My primary job was usually tuneup and electrical, plus the aforementioned emission testing and I think I'll be fine after driving/adjusting it for a bit. Trips will be short if this global energy convulsion continues.