Ford Repair: 87 efi, speed density, intents and purposes

Question
im wanting to put an 87 f150 302 efi into an 85 f150 carborated 300ci and also would like to stroke it to a 331 making around 400hp.  My ? is what do i need to do to keep it speed density and make this much power?  I hope you can help me with my situation !

Answer
Brad-

  The problem with that amount of power and a factory speed density setup is that it's next to impossible to acheive.  I say "next to impossible" because technically nothing is really impossible, but for all intents and purposes, it won't ever happen.  Even back when these systems were new and people were squeezing as much power as possible from them, you had a "beast" if it made around 350hp...and that was usually the product of extremely extensive tuning and retuning.  Current aftermarket speed density setups could easily make that kind of power goal simply because they're programmable whereas the factory setup is notoriously inflexible.  It has a built in "safe zone" where it adds just a bit more fuel than you need, so every airflow modification you make chips away at that safe zone.  You can make more power by fiddling with fuel pressures and injector sizes, but there's a limit to what can be done and these days anything over 300hp or so is almost unheard of.  If I were you I'd either go with a mass air style system or just use a carb.  Either way you could see 400hp relatively easy.  Hope this helps.

Steve