Edelbrocks base tuning is extremely rich out of the box and their AFR targets were insanely rich. With the cats on it, I am targeting 14.7:1 at idle and cruise and 12.5 in power enrichment they call acceleration. With this mild near stock like 6492 cam it burns very cleanly and is getting excellent fuel economy cruising around even turning ~2,750 rpm at 70 mph. The gear ratio calculator shows it should be turning 2,600 rpm @ 70 but with the TH400s non lockup converter it is a bit higher. ~150 rpm slip cruising at 70 mph is not all that much for something that is flash stalling nearly 2,800 rpm. On level road it is pulling about 18 in/hg vacuum cruising along at 70 mph, plenty of torque in reserve to climb grades and accelerate in high gear.
Oh I also ran it on 87 to start with 14* initial and 29* total timing at 4,000 rpm. I put 93 in the tank, bumped it to 16* initial and 34* total at 3,600 rpm and it woke it up like crazy. With 34* total commanded initially it was showing 36* total. Ended up that it was due to the vacuum advance adding timing with the air cleaner restriction. Pulled it back to 32* commanded and it now runs 34* total that I had initially wanted it to. 10.25:1, 0.038" quench, aftermarket iron vortecs, tiny cam giving 195 psi cranking compression, 93 pump gas, 34* at 3,600 is seeming to be about perfect.
The Proflow 4 out of the box also had the deceleration fuel cut-off set for 1,200 rpm as a minimum, it was not overly happy with that setting. Idled tended to dip a bit and it would try to stall before it recovered coming to a sudden stop. I copied the GM L31 tunes and set it for 1,500 rpm. It is much happier with that RPM value.
I also have a theory to try out on the throttle body minimum air idle screw. It has a tendency to stall going into reverse when it is cold as well as when it has been driven and sat a while with the coolant temps between about 100F and 140F it tends to flood a bit on restart. If I crack the throttle it starts much more easily. If I crank it over without throttle, tends to flood out and have to open the throttle a good bit on the second cranking attempt and it blows some grey fuel smoke when it lights off. I have the crank fuel set at the minimim value allowed. I am going to open the throttle plate up enough to make it idle about 50-100 rpm over the commanded idle speed in Park/Neutral thus getting it more air when cranking and right after startup.
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