WakeRider89

Currently looking to build up my 2003 Silverado up to put the sad SS's to shame. I have a 4.8L stock looking to do a cam swap to something mild, change out pistons/rods/rockers to 5.3L stroke, LS style intake for clean look, throwing in a turbo kit with intercooler, and looking for cheap solution to better heads.

Computer swap is probly a must with this too im sure?

Trick flow has a 5.3L top end kit
http://www.summitracing.com/parts/TF...ComboContents/

My only issue with dropping 3k on this kit is the price of the heads alone! Is it possible to modify the stock 4.8L vortec heads to put out some more hp?


This is my first engine build and any help will be much appreciated!

Darkman

iTrader: (2)

I would call Total Engine Airflow, Advanced Induction, or one of the other sponsors that assemble heads. If you end up buying those heads these head specialist give you specifc advice on your particular application and then can assemble the heads to you specs and chosen components. Additionally, they can also tell you about other options such as reworking an existing set of heads.

joeyc125

iTrader: (7)

For the money you will spend on those heads, you could buy a boneyard 5.3 that has the proper crank, have it bored to stock 5.7L specs, use decent parts and make the same power you would with those heads at the same boost level, but have the ability to up the boost a little more and have alot more power. After you get bored with that, then get a good set of heads to compliment the rest of your build.

The_Rizzle

iTrader: (4)

I think you should stick the boost to the 4.8, since changing the 4.8 over to a 5.3 is a LOT of work for not much gain. You'd have to pull the engine to do any kind of a good job anyways, so if you're trying to up the displacement, either bore it over to an iron 5.7 (you'd still need a 5.3/5.7/6.0 crank) or go find a 6.0l.

OR

Boost the 4.8 till you're not happy with the power anymore. I'm sure you'll get your truck pretty fast with it.


BTW, 4.8 heads ARE 5.3 heads. They are also almost ls1 heads, just with smaller intake valves. And smaller chambers.

WakeRider89

Maybe I should have explained myself a little more. I like all of the advice so far but this is my dd and gotta keep gas mileage in mind..... so i'm not really wanting to go the 5.7 route as much as i'd like to!

Rizzle you answered a few questions I had. So if I up the crank, toss in some headers, maybe turbo, and computer flash I would probly be upping some considerable amount?

What do you guys think would be the smartest route to go until I do a straight up overhaul?

claytonisbob

iTrader: (1)

Get a 5.3 pullout, they can be had cheaper than trying to swap parts into your 4.8. Better yet keep an eye out for a LQ4, they're out there and not that expensive when compared to that top end kit you're considering.

The_Rizzle

iTrader: (4)

Making your 4.8 into a 5.3 would basically be your overhaul. Heads, pistons and crank all have to come off/out of the block do do a switch for not much gain.

You can't just "throw" the 5.3 crank in. the rods are diff lengths, and since you're wanting to boost, the 5.3 pistons should also be used (dished 8cc). To put rods and pistons in they have to go in from the top, so off come the heads. To do it anything close to proper, that engine would have to come out.

Boost the 4.8, look around for a 5.3 in your area, overhaul that one while driving your 4.8.

Yeroon