maxrock885

Im looking to build a 5.3 for my truck and I wanna be around 650-700whp. Single turbo seems like the best option. What are the power limits of the LM7 block? I assume I might need forged rods and pistons, so what would be the best bang for my buck? I would also like a choppy cam, and was thinking about going with a 76mm Garrett turbo, most likely will pick up used. Im trying to keep this build on the budget side of things. Ive got about 4-5k to play with so if you think doing a 500-600hp NA build better please let me know! also the last thing I want to touch on is reliability, I would love to have 650whp and be reliable while staying in the 4-5k range but I just don't know if that is achievable, I don't mind having to work on my truck considering I work on cars for a living but I also want to be able to turn the key on the weekend and not really have to worry to much. Im pretty new to the LS world so please feel free to hit me with a whole bunch of info!

FFDP

iTrader: (2)

I would up your budget by $5,000ish just to have what you want. No way a 4L60e transmission will live behind that much power. You need a 4L80e for that.

The block isn't a problem. You can run factory GEN 4 connection rods and forged pistons. Any camshaft can be a turbo cam. A stage 2 or stage 3 or a specific Turbo camshaft will make gobs of power with a turbo.

Add the turbo kit now and then don't forget about the beefy fuel system to handle that power.

Running that much power on regular pump gas will also want methanol injection. If you plan to run E85, then you need even larger fuel injectors than something ran on 93 octane. E85 needs about 30% larger.


And for what it's worth, 500 horsepower at the rear tire will do burnouts for days. Do you really need 700whp if it can't even put power to the ground at 70mph?

94heritage

Simple build would be 80e, any good cam. If it was me i would look in the high 21x to low 22x duration s475x83 in a 1.10 or 1.24 t4. Did a combo for a buddy in a k25 sqaure body truck with the summit high lift truck cam 218/227-112 and it has a nice chop and makes great low end tq and have yet to find where it quits making power. That combo would clear 700 tire with ease and make for a great driver.

imma_stocker

iTrader: (19)

The whole point of using a Gen 4 ls motor is the stout bottom end.... why tear it down when they are proven capable of 600-700hp? Focus on trans, fuel, and tune.

madracer402

My little truck made 718rwhp with stock Gen 3 bottom end , cam , re gapped rings , new bearings , 210 injectors , 525 pump, intake and a summit turbo cam on 17lbs .. (definitely junk the 4l60 )

RDF1

I get alot of folks wanting 1000hp trucks and then they drive it with 600-700whp and they change their mind pretty quick.
We have made 1480hp on stock bottom end gen 4 5.3s. Fuel is your limitation every time. On pump gas 91 or 93 just stick with about 550-600hp and you will find out its not gonna hook up good in a 2wd with factory suspension.

For a regular cab 2wd and a stock 5.3 i found a 218/222 cam motion worked good with a S475/87 on 93 octane and a 3600 Circle D converter (4L80E), 3.42 gears and 28/10.5.
Ran low 11s spinning thru first and second gear.

Is this going in a regular cab 2wd? or a crew cab 4wd?