I knew a guy with a 1985 Grand prix. He put a Pontiac 455 in it and had a GTO hood tach on the hood too. But he ran the stock HEI ignition. I asked how he got the old style hood tach to work with a modern HEI but he did not know. A shop had rigged it up for him. Is this possible? I thought the points tach would NOT work with anything but points. I know there are aftermarket hood tachs that will work with anything. He claimed he paid a fortune for a genuine GTO hood tach so I am baffled. I know that when I had my '68 Firebird and I put an HEI in, the Cal Custom Hawk tach would not work. I eventually used an MSD box and even that needed the MSD adapter for the old tach to work. I am asking because I have a couple of original Firebird hood tachs doing nothing right now.