okay so i have a 98 2500 that didnt come factory with cab lights whats the best oem solution to do and any tips on doing so 

thanks!

Pull the headliner down and you will see the holes you need to drill from the inside out. I believe I used a 1&1/8" holesaw on mine. You will need to get measurements from a truck with factory cab lights in order to get them straight. Or I think you can buy a kit from dodge with a template but that may only be for newer trucks.

Awesome thank you!

Here’s how I did it, done this a couple years ago during the winter, I didn’t use a template nor did I have another truck to measure off, you really don’t even need a tape measure either

 

after removing the overhead console and headliner, I used a spade it the same diameter as the factory holes that are punched in the sub roof, this is just to get a mark dead center of the hole

Then just drilled with a small pilot hole up from the bottom 

Then I moved to the top and drilled down with an 1 1/8 hole saw 

I used these factory teardrop lights off a 96 dodge they came with the factory harness too. If you are using this style you will have to move the light forward of the hole about a half to 3/4 inch to allow more room for the screw holes around the large hole

The gaskets were also in good shape, and just to make install easier and mess free and if I had to change a bulb in the future I did not use any sealant either, couple years later and no leaks