I have a 92 civic with a single overhead cam vtec in it. I am unsure on how to hook up my shiftlight to the actual vtec. My buddy told me I didnt need the expensive 5" tachometer with the rpm, he said I could hook the shiftlight up to my rpm gauge from my gauge cluster. So I bought a seperate shiftlight for 50 bucks at jegs and am yet to hook it up. Can someone please help me out. Pics attached.