ok, just purchased through the mail a used factory original tach dash.(obviously without seeing it first)- the dash housing is busted to hell and unserviceable. also pigtail wiring harness is cut. 1st question, in all the resto catalogs i find, replacement tach wiring harnsses stop at 74', will it work for my 79' ? 2nd question, will my present (current) dash housing work with a swap of the print board, guages, and face shield (the boughten one has a nasty scratch). is this going to be an easy install, is there any other considerations to worry about ? should i refer to a service manual to install this, are the wires easy to i.d. ? or should i have it professionaly installed to make sure everything is correct ? any and all info will surely and greatly be appreciated ! darrenolander galva,il. 1979chevycheyenneblazer 350/350 gettin'down on all fours, 4 a'little x4 play !