Help for build plan

[Hamin9l]

I have a 2002 1500 that has the 5.3l lm7. I'm gonna have to replace that engine in the near future so thinking ahead I bought a engine for $50 bucks. Iv stripped the whole engine down to the block. I'm looking for a clear plan on getting 400hp out of this replacement. It has 706 heads with it, id love to reuse those but I'm not apposed to getting something else. There is so much stuff online about these engines its hard to get a clear plan. Trying to keep this as cheap as possible while still achieving my goal.  So if anyone has experience with this I'd love some help. 

[CamGTP]

Making the engine bigger would make 400hp easy, like making it a 5.7 or 6.0.

 

Otherwise you need to know how you want this engine to act. A 5.3 can make 400hp but it won't daily drive that well and you'll need a nice stall converter plus built up transmission to handle that power. Along with other odds and ends to support 400hp.

 

If you drive this alot I would do a 212/218 or similar sized camshaft, mill the cylinder heads a tiny amount to raise compression. It would be a good idea to upgrade to 31lb or 33lb injectors to support the extra power. Injectors can be found in other stock truck applications, the data is plug and play for tuners if they have the files. Do some long tube headers and hope the stock transmission you have can hold up. This should be a 50-60hp bump over stock if done right, probably low 300's at the tire.