Thanks to whoever posted about cutting the bowl out of the stock air-cleaner housing. It's amazing how much difference 5 minutes and a zizz-wheel can make. Old Girl pulled the horse trailer much smoother and quicker. Pulled one day, cut it off and pulled the next day. Great free mod.
Ok, now, tach just suddenly quit. Should I replace the sending unit first? I know my rpms when normal, but not when towing. Too good a truck to risk for no reason.

 

check the wires around the sending unit and also try removing the sending unit and cleaning off the end of it.

 

Thanks Crawler. I'll try that soon as I get home.