Remember something about the guys taking a small hack saw and cutting a notch in the base by the plug where the mixture adj screw is hidden. Then they would take a small punch to remove the plug to expose the adjustment needle. Its a tamper proof thing that Ford did to try to make that horrible emission engine comply. Don't get your fur up, the engine is great, just not a green engine, just like the 360/390 engine family, not very fuel efficient.
Ok I'm gonna try both of those tapping first then the screw access secondly.. We tried using a screwdriver to roll the shaft over behind the screw just buy pushing up against it but I think it actually think it may have been a tube casing the adjustment screw shaft.. Thank you bill for at least giving me the answer to the mystery of why this is designed as such haha was driving me batty
Ok so I pursued what I thought was the adjustment screw but it wasn't I don't think. It had a cover over it but it was pretty much just a structural bolt, when I turned it one way it turned the throttle mechanism up and revved the engine, wouldn't turn the other way because that was end of the line, no where to go below idle... Does anyone know exactly where the lean/rich adjust actually is? The person who told me it wasn't adjustable obv was looking at the wrong screw so maybe it is adjustable???