i know i'm going to get crap for asking about such a common topic but i searched the forums and could not find anything relevant. my truck is a 96 f150 4x4 with a 171,xxx mile 302 auto. obviously the 302 isnt a powerhouse but has served me well since i've owned the truck (roughly 20k miles). the truck has never had excellent gas mileage and recently i opted for 31 inch tires which brought the mpgs (and power) down even more. i've been toying with the idea of swapping in a 351 with some slight mods to help the truck get going a little easier. ebay has a few good looking doners but none are from a 96 vehicle. my main question is would these engines work with my OBDII truck? and if so, is it worth it? im looking for more power for my heavy foot and my gas mileage cant go down much more than it already has. most of my driving is on highways with some around town. also my truck has the 3.55ls. any advice is welcome. thanks!