those running 5.3's
 

how many miles did your 5.3 have before adding boost to it? Did you do anything to refreshen it?

51,000 on an otherwise stock LS4. I've never removed anything from it other than the front manifold to replace the thermostat, not even a valve cover.

So what does it make, and for how long?

It made 370 hp with about 5psi at the gauge last fall. It has 56000 miles on it now. I had some tuning issues early on with it stumbling at wot. That was cleared up at the expense of tuner pulling timing to help fix problem. I'm running 10.5 wastegate springs now seeing about 9psi at the gauge. No new hp numbers yet. I'm having it retuned this summer and switching to speed density. I had a fuel issue that was finally resolved by taking the car in to the dealership. They replaced the fuel pump, fusebox and replaced the pins in the fuel pump harness a couple of months ago. No issues since. I have yet to do anything to the engine itself. Knock, knock.

Do you beat on it often or just cruise for the most part? Im going to change mine out for a 5.3 soon and thats why Im intrested. thanks.

Mainly I just cruise. Everyday I pull a way from a stoplight at least once for an agressive 1-2 shift rush. No quarter mile stuff though or just going out flogging for the hell of it. It's all I have to drive so I can't afford any breakdowns.

So you have put roughly 4k on it since the boost was added? If the ls4 5.3's are as tough as the truck iron block 5.3's then Id say you have nothing to worry about. My stocker has 178k on it and I dd it 110 miles a day. It has been boosted for roughly 10k so far and I usually just do 60-120 blasts when the need arises :devil:.

I put a magnacharger on my 5.3 at 90k. At 150k I switched to a turbo. It put 320 to the wheels with the s/c and 500 with the turbo. I was a track whore for 2 years. It was a DD that saw about 30k miles per year. I broke a piston at just under 200k miles.

What kind of boost did it take to make 500rwhp and was it completely stock longblock or??? BTW thats good info. I plan to replace my 180k engine when this one goes but cant decide if a cheap 5.3 or a 6.0 is the better way to go $ vs hp wise...

I found a 5.3 with 160000 miles for 200. what do you think?

if the pan isnt full of sludge and such, id run it without hesitation. Hot Rod magazine did a 5.3 turbo with 150,000 miles and made high 5XX hp non intercooled, and after they took it apart and said bearings and stuff looked totally fine. good luck!

We've done several motors over 150k miles and worked great, my aluminum motor has the least miles of anything we have built at 100k miles.

I will be adding rodbolts/head studs and plan on making 550ish. Quik made 700 with just rodbolts on his 4.8 spinning to 7500 on 16psi.

Wow 700 with a stockish 4.8 and turbo? Thats crazy, you can buy 4.8's for $200/piece too. Later

Where, I need one, haha!

It was a while ago, but I believe it was 9 psi. The only thing that was not stock were the 918 springs.

I got my lm7 5.3l off ebay for 350. The guy shipped it to me for free and it has 140,000 on it. I might eventually rebuild it, but I'm just going turbo it and not worry bout the miles. Imo, if your going to crazy with boost, I'd go with a truck cast iron motor. I hear they are stronger.

I got a 5.3 from LKQ, high mileage, but mileage didnt matter because i couldnt care less how far its traveled.... but it was in decent shape. Lasted 3 years of some serious beating making 640hp to the wheels. Stock bottom end was never touched.
Mileage is for warranty stuff... its meaningless with engines. 100k miles on a truck with 4.10 gears will be different then 100k miles on one with higher gears. Driving habits, maintenance, ,.... etc. 10 different engines from 10 different people all with the same mileage on them will all be different.

My buddy has a cast 5.3 on 11psi and beats on it hard every day for the last 6 months and has had zero problems. It is 100% stock.

This kind of info gives me hope, do you know his #'s or how many miles he has put on it, how many it had when he got it? Thanks.