I have a problem with my 87 gt I recently just put in a new brake booster in and now I have no head lights. I have brake lights and marker but no headlights

 

I'd start by looking for a pinched/broken wire around the booster area. Sounds like one might have taken an inadvertent hit or yank.

 

I went through the same thing last week....After getting my car from the paint shop. They didn't hook everything back up like they found it. It was a grounding issue. Make sure both sides have a good ground. im almost positive this is your problem.