Hey guys! Just got an 88 f250 5.8 efi completely stock and was rebuilt about 30k ago, and I was wanting to add an edlebrock too end kit but none of them have efi, so was going to purchase their efi intake manifold and heads and cam separate, their efi intake manifold with k&n air filter and new throttle body adds 50hp but I was hoping to get to 350-400 and I have been told that a good set of heads and a cam will do that no problem, so I was wondering what I should get, I want really good low end as my truck will be used mainly for work and towing, I also got a set of long tube headers and plan on doing a full exhaust with no cats. Any advice would be much appreciated