Scott, there should be a tach terminal on the end of the MSD box. Use that, and if you want a real speedo needle, shoot me a e-mail with your address and I'll send you one - no charge. I have a left over from a Chevy truck dash I bought for the tach.
Depends what brand of light you have. Most need a "box" and a plug in module to make them turn on when you want them to. Proform makes a stand alone light that has a dial to set the rpm's, and some lights are made to be used with MSD's programable ignitions. Do a search on the net for the brand and part # you have. You may be able to find the installation instructions and wiring diagram online.
One more thing about shift lights. On some tach/shift light combos, if you disconect the battery you will need to reset your shift light. They must not have any memory other than what is retained by power from the battery.
I have an MSD RPM Activated box that works great, uses MSD rpm chips for the light and it works flawlessly. $60 from Jegs and the part # is 8950. I know a lot of racers that use this as well and they all like it's funtion.
Hope this helps out!
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