I have heard about putting a 2 barrel intake on the motor will give me better mileage. If I did that I would probably buy a new holley two barrel or a demon two barrel. The demon comes with an electric choke and is not much more expensive than the holley.
Well, I've heard putting the factory SUPER SIX 2bbl (Carter BBD) can provide better mileage, and it did make a difference in MY case, but I'm not sure one of the bigger aftermarket carbs would help MPGs (although it would certainly make it more fun, if tuned properly...;) ). There is an electric choke conversion for the BBD if you really want one, but my mechanical choke works fine.
Do you recommend headers and if so what kind, also what should i do for exhaust? I wouldnt mind having a duals or just a dual tailpipes would be fine mainly for the look, but if it hurts the drivability then I wouldnt do it.
Dutra Duals are WONDERFUL, and preserve the drivability by retaining the carb heat (which, unlike a V-8, you WANT with a slant six). The only downside with dual exhaust is carrying the unnecessary extra weight (the only benefit being the looks and sound). Dutra duals merged with a y-pipe to a 2 1/4" single exhaust is generally considered the optimum slant six exhaust.