Cowboy Tom

A few months ago I bought a 2008 Silverado LT 2WD ext.cab std.bed with 5.3L, my plans for the truck is a mild performance truck with an aggressive off-road look so I do plan on doing a leveling kit and slightly bigger A/T tires,
Truck is rated at 315hp factory, my goals are, (I don't plan for all 3, just which ever one comes first) 400HP, 5.5sec 0-60, OR 13-14sec in the quarter, so far I've only got a Hypertech MaxEnergy tuner, and just got a Powerstop slot drilled rotor performance brake kit, I plan to install tomorrow.

My plans are cold air intake, aftermarket MAF, TB spacer, larger TB, true ram-air hood, MSD ignition coils, hi-flow cats, cat-back exhaust, once I do a few upgrades I plan on doing a custom tune, and two maybe's are headers and 3.73 gears (3.42 factory)

--So questions are best guess where I would be at with those upgrades? What would it take to get roughly 5.5sec 0-60? And can my factory transmission handle 400HP

Thanks for the help

GMCtrk

iTrader: (27)

Those aren't upgrades. Those are you pissing your money down the toilet and in some cases downgrades.

The only real mods worth a damn n/a off the top of my head would be live custom tune (not mailorder), headers, cam, gears, aftermarket torque converter.

07NBSChevy

To achieve around 400 (crank hp) in a 5.3, you will need a small cam, headers, Airaid tube and a good tune. Which will equal out to around 300-320 rwhp depending on cam. You will need major valvetrain, headwork, large cam to achieve maybe 380-400 whp, which your looking at $6-8k and wouldn't be street friendly. If you want over 350 rwhp its cheaper to do a 6.0, or forced induction. Also your 4l60 wont take much over stock ratings. A mild built one should handle 400 crank hp. And i agree with GMCtrk, those are a waste.....coils, MAF sensor, and TB spacer are worthless. Stock is just fine. Check out my Sig, I should be around 320 RWHP when i do the cam swap.

Jake75

iTrader: (2)

i made about 390 before i went turbo. I had port and polished 243s, 226/230 cam, 3600 stall, headers and air intake.

TheAutumnWind

Listen to this guy.

Cowboy Tom

Alright thanks for the info, gives me some things to consider, I thought about a mild cam, but I don't really wanna go internal. How much of difference do u think 3.42 to 3.73gears would make, I've thought about 4.10 but I don't wanna kill my fuel economy? My old truck I went from 2.73 to 3.42 and made a huge difference in acceleration but little to no difference in fuel economy, but that truck had 33's so it probably needed at least 3.42's

07NBSChevy

If you want a cam that wont lose any lowend stay under 210-212 intake duration and 218-220 exhaust duration. Max lift for stock heads is around .551 and 112-116 LSA depending and how strict your smog sniffer is and how you want your idle and powerband.

You will have to tear the engine down to a shortblock to do this. You will need to change lifters, lifter guides, valley cover, valve springs, pushrods, new head bolts, 3 bolt 4x cam gear, and i recommend LS2 timing chain and tensioner.

Gear size depends on tire size. I run 31.6" and run 4.30s and didnt lose any mpg. I will end up going to a 32.8" tall tire. But in my opinion 4.30s are ideal for towing and highway for a 4 speed with my tire size.
My opinion
Under 31" - 3.73
31-33" - 4.11 or 4.30
Over 33" - 4.56
This is if you daily and drive highway

TheAutumnWind

LT's, torque convertor, a real tune, servo's, gears would get you a lot faster in the 1/4. Off road tires would definitely not help of course.

gamble686

iTrader: (3)

to use a golf analogy you are missing the mark by a couple degrees and it's causing you to slice way off course. First things you will want to do are the supporting mods.
1) ditch the handheld tuner and get a custom tune from a reputable source. Tell us where you live and we can give you some good options.
2) I am guessing you have the 4speed automatic(4L60e) you will want a larger trans cooler and the Vette servo ASAP.
3) gears are a great idea. This will give you huge bang for your buck. I think guys have given good opinions on ratio to tire size. I personally love my 3.90 gears, but would recommend 4.10 or higher if you go with larger tires.
4) if your doing gears get a posi/locker done at the same time the factory one is garbage
5) boltons. Longtube headers, magnaflow muffler, cold air intake. These will help get you moving. I wouldn't do a complete catback as its a waste of money when stock piping is 2 7/8" and a 3" exhaust will I've you very little bang for your buck.
6) the next mod is a torque converter and cam. I put this together, because they should be speced at the same time. This is all about how much effort and how aggressive you want to go. For a mild setup the tried and true 212/218 low lift is right up your alley. Matched with a circle d 278 mm budget stall you will make great power for reasonable money.
7) if you need more come back and see us, FI, internal work, more cubes etc is a whole different can of worms.

bobfig

easiest thing would be to do long tubes back, mild cam, and custom tune.

i would look into the BTR truck stage 3 cam along with springs and afm delete.

if you really want to have fun get those 799 heads ported by some one good and will defiantly make it.