This is just phase 1 of the build but what would a rebuilt 5.3L lets say a bone stock 1 with ls intake with maybe ported stock heads and a procharger pushen 10psi, 3 core fmic and full support mods, and a tune do?

Im also thinking about just putting forged parts in it and mabye 15 psi and just making it pro-boost only.

4l60E
10 bolt 3:73 (with parts in it)
DD street car

Post up on LS1tech for number guesses

I will tell you the 4L60E will survive a few dyno pulls at 15psi before breaking just about everything. The 10 bolt, even with help may last a handful of sticky launches

no launches....just a tire blowing street setup. ; )

-plus that is just phase 1, getting it in the car.

youre going to need a build 4L60 or a 4L80 to back that kind of power. Not to mention, either a 9" or a 12-bolt out back. It doesnt take much to tear up even a mildly modded 10-bolt rear.

Even if all you want is a tire blowing street setup, eventually those tires are going to grab and it wont be pretty.

When i finally do an LSx swap, i will be putting the engine in with just a cam and the supporting valvetrain(if needed) to start. If i get bored with the power ot hungry for more, i can do a head swap and the rest of the bolt ons.

I would say take it easy to start or youre going to turn that car into a HUGE money pit.

Boost is a money pit, fact of life

Dumb buddy talked me out of my blower build....*** hole....might keep my double nitrous setup though if I cant sell it for at least what I got in it. What say a rebuilt 5.3 with rings and bolts ported stock heads and 150 shot do?

Break more parts....

From what i have read from some trucks sites, is that its the same problem. The engine will take the 150 shot just fine all day. (with a tune) Its the stock trans that wont hold up long. But i'm about to put that to the test. My 5.3 is stock other than the cam and springs. So i will be spray either a 125 or 150 on mine real soon with a mayheim motorshops tune, and a WOT switch. Some say the trans will last longer not spraying through the shifts.

but what will a stock 5.3 with say 150 shot, DRs, 3:73 and a good launch run with full weight, minus a/c, emissions and radio stuff?

.......good......

ok, so whats a good setup to make 450whp? with out the spray?

A very big cam and bored. It would be a lot if work to get 450 WHP out of a 5.3 without boost or nitrous. 450 flywheel is very possible.

So i should save and get an lq4, I picked the 5.3 because it would realy be the only way to afford the swapp.....esp when I decided to get a swap harness.

--also is buying a FAST or ls6 intake worth the big bucks? I heard it only nets like 10-12 hp. and which is better, the LS6 or a fast?

I would go with the 5.3 if you already have it. Also I would look into doing your own harness. Its a lot of work but its worth it in the end because you will know you car inside and out. Pocket has made great wiring threads and all I did was follow it word for word. I would use that extra money that you would spend on a harness and invest in a cam or getting that trans ready to handle more power. Also I know you looking for a certain HP goal but are you looking to take it to a track? Because you can have really go track times with 400 whp.

I dont realy go to tracks, swap harness is me taking the easy and clean way out.....

-I dont have a 5.3

So what are some good/decent (-affordable-) heads and cam to do for a 5.3?

I personally wouldn't change the heads , just the cam springs and pushrod. After reading that article in I think car craft or chevy mag. Can't remember but they picked up 100 HP from a cam swap and only about 20 or 30 from porting the heads. I would get something around a 228/228 with .588 lift on a 112 lsa. And a good tune that should net you around 350 -360 @ the wheels. And I would really invest in the tranny and fuel system so in the future if you what to go boost or nitrous you would be ready. And will be good to have a stall converter for that cam too.

Thanks, ill keep that in mind.

yeah saw that article too, it was on a 150K mile iron 5.3 from the junkyard too. if you start with an L33 5.3 and get a good cam w/springs/rods, swap to an LS6 or fast intake, run LT headers and get a good tune, it would be pretty close but im talkin about running through a T56, less power % loss.

i spend a lot of time on the ls1truck.com and performancetrucks.net and seems to be the tr220 cam and good set of 243 or the 799 heads maybe with a little mill work seem to work great. my cam only setup im doing in my 03 yukon should get me in the 340whp range. its very possible to get 400whp with a 5.3 on stock bore size but really have to plan your head and cam and intake combo acordingly.