Chiphead

iTrader: (2)

Hi Guys, I'm new. LS1.com sent me over here.

My 04 Silverado has a 5.3L with the cracked castech heads. The motor is high mileage (180K) and is sludged up from the coolant leaks. I see plenty of used engines on Ebay and new ones online, but I need to know which ones will drop-in. I think my engine is a GenIII LM7. Will a L33 or other engine codes fit? What years are compatible with my electronics and fuel system? What head casting numbers do I want on a replacement engine?

thanks!! Robert

Chevy_King1500

iTrader: (7)

Anything 99-06 5.3 will drop in.

Chiphead

iTrader: (2)

*edit* A few more questions....

How much are running stock 5.3L "L33" salvage engines worth?

Can I swap a '05 ECU (from a L33) into my 04 wiring harness to run the L33? Or how hard is it to put the stock 05 tune on my 04 ECU?

SnakeOiler

iTrader: (6)

You also have the option of 02-06 6.0L as well.

No need to swap computers, just have yours tuned.

1Bear

iTrader: (1)

You can also expand out your search a year in each direction, as the ’01 and ’07 Classic’s are viable candidates. Everyone always gets mixed up with when the aluminum headed / short crank 6.0L’s entered the scene and with the GMT-900’s being released in ’07, they get dropped off the list due to people forgetting about the Classic models still roaming the dealerships that year. Of course that only covers the Gen III 6.0L’s and as far as 5.3L engines go, one could use an even earlier model if chosen. Of course I would suggest and prefer a later model over the earlier units due to the various improvements over the years.

Chiphead

iTrader: (2)

I'd be happy with a 5.3L that's reliable. This isn't a project or show truck, just my daily driver. I can't see putting a high dollar crate engine or complex swap in it. I've gotta drive it home Friday, swap the motor and drive it back to work on Monday. A local shop wants $1,900 just in labor to do the swap. I can't afford that and the truck isn't worth it. I've got a '67 LeMans drag car and a '54 Bel-Air resto-mod project. I've got plenty of other things to work on, but luckily that gives me the tools to do this engine swap in a pinch. I am fighting the urge to do a 6L swap or something nuts, but I keep telling myself I'm in a bind and I don't need another project.

What do you guys think about a reman stock 5.3L from Jasper? If not Jasper, then who makes good remans? I wouldn't have to do anything but install my bolt-on parts and drop it in, right? Thanks!!

BattleSausage

iTrader: (3)

My personal opinion who be to seek out a low mileage L33 off of CarPart.com. I purchased my last one from there for $550, had 66k and looked like new internally/externally. . It's a direct swap, so everything will swap over including the flexplate. It'll make great stock power, and it's just a cam swap/head work away from excellent power and should you choose to go FI down the road, you have better cylinder clamping on the smaller bore. It's lighter to boot. The 6.0 would be nice but the 5.3 is a very capable platform, and cheaper.

Chiphead

iTrader: (2)

I was talking to an ASE mechanic friend of mine yesterday and he asked why I didn't just change the heads. I wanted a more powerful engine, but it made me think... At 180K, my oil pressure is still good and it seems like the motor still has good ring seal. The bottom end isn't making any noise. I could flush the crankcase out and swap the heads and it would be much easier. Maybe some bolt-ons or a cam swap while I was in there. Can the oil pump be changed without dropping the pan?

Any reason I couldn't swap on a set of milled 862s and run it like I stole it? How far can these heads be milled before I run into intake or gasket fitment issues? I see some good looking 862s on Ebay but I don't know what questions to ask.

Chevyboy203

[QUOTE=Chiphead;5186737]Hi Guys, I'm new. LS1.com sent me over here.

My 04 Silverado has a 5.3L with the cracked castech heads.





hay if u need a 5.3 I got a 2003 Silverado 5.3 waiting to be taken out and swaped with a hi performance 5.3 pushing 425hp 10:25:1 cr is getting put in if ur intested runs great can even send u a video of it 120k miles 630-842-0657 in ct

CMAR81

short block re-build is another option...should cost about 1k, and if your a decent wrench turner you should be able to accomplish the R&R in a weekend... not for everybody, but was the route i went and got it done in a weekend.