A month ago or so, somebody made a comment that I may have to change the step up spring on the metering rods on my Edelbrock avs 1806 carb due to running the 200-4r transmission. Can someone chime in on this and point me in the right direction. I swapped metering rods this weekend and secondary jets as I was running rich. The step up spring that was in there was orange. I went 8% leaner as I was running rich enough that I could smell it while at a slow cruise, and under WOT. Making it leaner definitely helped bring out some power. I do not have an A/F meter. My guess is that I am pulling lots of vacuum while on the highway in cruise mode and could get better mileage. I have 3.36 gears, 255/60/15 tires so my rpms are low. Will I get better fuel mileage as I can run it a little leaner with a weaker spring - Pink one? Should I run a vac gauge on it while cruising on the highway and see what vacuum I have? At idle I am at 16.5 steady.
What does it do if you mash the pedal? Usually with a bigger cam you need to go to the stiffer "plain" springs, but it really depends on the engine. My driver has a 1406 and I've got the lightest springs (blue) in it as the vacuum signal isn't very good and with the standard orange springs, I have about 5 seconds of nothing before it'll let the rods out of the secondary jets when I mash it. Look at which hole is your accelerator pump is in, it may be giving it a squirt when you don't need it to.
It runs and drives great, stock cam. I don't have any dead spots throughout acceleration. Accelerator pump is in the middle of three holes.
Without an A/F meter you're just going to have to go off seat of the pants and testing back to back doing plug readings. Usually on the Edelbrock carbs, if you haven't got any rich smoke or lean hesitations you're doing pretty good. You could try moving the pump rod to the leaner hole, but I'm betting you're pretty close tuning-wise. I'd maybe try next step leaner on the primary jets and see if it still runs "right" without a lean bog and keep going down until you do, then jet up one or two....to your original question of having to change tuning because of the overdrive: I don't see why you would need to. If it runs right in 2nd gear at 1800 rpm, I don't see why it would make a difference if it's at 1800 rpm in 4th (just an example). I've never had one on a car with overdrive, though, so I could be wrong.
