Best (easiest) fitting headers 68 Cuda 318

I'm not sure about the best, but for a shorty header these are easy to install. You didn't say if you have a manual trans or auto. If auto there is a modification to do. If you have a manual trans you need the mcmaster starter.
http://www.ttiexhaust.com/Category-ClassicHeaders/34025-Shorty/TTi34025.htm