A pusher fan is mounted ahead of the radiator and 'pushes' the air through the fins. A puller fan is like the stock fan--it pulls the air through the radiator.
I have heard that the exhaust manifolds from a later F-150 with fuel injection are actually two pieces. The front 3 cylinders run on the front manifold and the back three on the back manifold. If you run this setup, run dual exhuast pipes all the way. This will not only make the engine breathe a little better, but it has a very unique and 'sweet' sound. Had I not bought all the exhuast pipes from the engine back shortly before I overhauled my pickup, I would find a set of these manifolds. Along the same lines, Clifford Performance
www.cliffordperformance.com carries aluminum 4 barrel manifolds for 300 sixes that are supposed to really wake them up.
You might also try
www.inliners.org--they are all about inline engines and like 300 Fords.
Good luck!
