I have a few questions on installing a dome light on my 70. The car was without interior for a long time so I don't remember how it went in. I think it had the wrong one installed anyway.

I have the rectangle dome light, first of all, does the short end or the long end of the base face the front of the car? Also, I can't seem to find any screwholes for the base to attach to. If somebody has a pic of diagram they could post, that would be great.

Bump!

The rectangular dome light is the correct one for '70. The long end of the base faces the front of the car. The short ends face the sides of the car.
The base should be held on by at least two phillips-head screws at opposite corners under the clear cover.