Has anyone done a new painless Wiring Harness? Under the dash, for the harness that plugs into the speedo etc. the wire colors dont match. Any suggestions?

Factory Fit are the better ones from what I have read around here and heard locally. I think Ames and classic both supply them. If it is too late to send yours back I guess you will need to match it yourself. I hope they have instructions for their kit, but you could try matching up with a schematic, maybe the ones from 1968firebird.org.