Did the same with mine back in the early '70s in my 340 Swinger. Local SoCal city police stopped me saying it impeded my forward vision. So I wired in a connector, put the unplugged tach in my glove box and got the 'fix-it' ticket signed off. Took the tach out of the glove box, hung it back up on the visor mount, plugged it in and drove off. Never got bothered again.