Ya, It can be ruff when your getting started, this Soeinoid, that Valve, ECT/IAC/EGR/EVP.........WTF??? You need to p/u a Maintenance/Repair Manual for your specific truck (yr/engine) to accelerate your learning curve. 1 BIG hint: Some parts are referred to by a couple different names! Understanding the difference between high compression & high rate of compression is helpful & "What is the purpose of Octane". This link will keep you busy:http://fordfuelinjection.com/?p=1 Research MAP & MAF 1 uses air density, 1 uses actual air flow to determine fuel trim & MAF comes w/ the added benefit of Sequentially fired injection. Also,"GOOGLE" is your friend!...............And when the dust settles, after checking Vac system integrity and insuring you have no active Error Codes, this should be the first Mod you do, and will compliment whatever you decide to do later:http://fullsizebronco.com/forum/show...ht=timing+bump.......The End!

 

How much est hp would this give a mostly stock truck truck? I've heard a 2-3 mpg improvement.

 

So are you wondering about HP or MPG? Either way, if you go to K&N's website they list how much HP on a given vehicle their products produce. I just installed a complete air intake on my 94' and it's estimated to produce 10.22HP, well worth the $280.

Just an air filter replacement, I wouldn't expect much.