Tech: Performance upgrade for Chevy Silverado 2001 K1500 5.3l Z71

My engine is rated at about 285 hp right now. I'm looking (hoping) to get close to 400hp out of it. Nitrous and a Supercharger are out of the question. Is it possible to get a big horsepower gain with:
dual exhaust headers bigger air filter etc etc... (smaller and minor engine mods). One other thing. I'm trying to keep the gas mileage around the same or better. Is that possible and have 400hp, or am I trying to have my cake and eat it too.
Can someone recommend engine modifications that will help? Also can someone recommend a place in San Diego CA that is reputable for doing this sort of engine work? Thanks...
-Pat
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Pat,
From the items you have mentioned I doubt you will see much more than 80 HP increase. It is very hard to make a huge power jump of the scale you want without a supercharger, turbocharger and or Nitrous. Out of all the things you mentioned headers would be the best bang for the buck. Next I would look at a chip tuning devise (Hyperchip e.c.t) and also do a K&N air cleaner.
I will be honest when I say that you are really working with a small motor size to get that much extra power and use it as a daily driver while also keeping smog legal. You are able to find supercharges that are smog legal. Other than that, there is a very true saying "there is no substitute for cubic inches". Good luck.
--
Regards,
Chuck
78' Chevy 1 Ton 4X4 Van
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no, 400 HP without juice and/or forced induction will require some serious internal mods, and gas mileage will suffer greatly. you're very much trying to eat your cake.
-Bret

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So you want to go from 285hp to 400? you won't do it by what you want to do. Doing what you want to do you may ge 10-15% more and thats all.
Good Luck Bill

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Thanks a lot for all the responses. When I was first reading exhaust upgrade kits for the pickup, they weren't adding very much horsepower, What are some of the headers that people can recommend? I would like it smog legal (if possible), and most horsepower, best gas mileage rating, etc...
-Pat
wrote:

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he he he....most horsepower and best gas mileage?? he he he....edelbrock has a nice complete set for your truck....quality is great.
b

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