Just trying it in neutral the ROMs are higher but it will still backfire and miss at a point.
My tac seems to be a bit finicky as well so I'm not sure I'm getting a good read. It will be bouncing at 6k but listening to the motor that is obviously not accurate.
Not sure if the tac is bad or it is a wiring issue or something else I'm not aware of with the tac read.
Got an update that may help some folks with this issue. put a new electronic distributor in it and it fixed the problem.
It was not a fuel issue or anything with the carb. The total advanced timing curve controlled by the distributor was not fully advancing so the engine was not capable of reaching max power.
Try a high temp range spark plug...mine were incorrect when I bought it and had fouling...switched to highest heat range plugs and this corrected the problem...I also found the carburetor had loose bolts holding the two chambers together...has run great ever since.