iregret

iTrader: (4)

I have an opportunity to buy a complete 5.3L LM7 for 275.00 on Craigslist. I know everyone's crazy about the 6.0, but I'm wondering if there's something to be said about smaller displacement and gas mileage.

I'm currently building a mild P1SC with a stock LM7, but in the future I'd like to go with a turbo setup with an 800 horsepower goal.

I've kind of been looking into forged internals and they're a lot more expensive than I thought. It looks like a complete forged bottom end is in the 1500.00+ neighborhood. There's also a kit to get 408 cubes out of the LM7.

Honestly, I'm not sure what to do. Should I buy the cheap 5.3 and then sell off the parts I don't need? Or pay more and try to find the 6.0. I've been looking pretty regularly for the 8 months and I really haven't found any deals on the 6.0. I did see one for 600.00 bucks and it was immediately gone.

It looks like around 1000.00 is going to be considered a good deal in my area. Is it worth spending 3 times as much? I want to go forged either way. I figure the cost to do so is probably similar either way.

What would be a good budget turbo friendly 5.3? Forged bottom end, 317 heads, TBSS intake, Z06 cam and valve springs. Then the upgraded timing chain, lifters, oil pump and ARP bolts throughout?

Remember, 800 horsepower (streetable), as cheap (and reliable) as possible.

Thanks fellas!

nonnieselman

iTrader: (10)

800hp at the crank or the wheels?

With the right cam/ turbo combo and head studs a stock LQ4 shouldnt have a problem making 800 at the crank with a really good tune and good gas.

On the built motor side of things you could take a 6.0 and turn it into a 370ci with the right internals and make 1000hp at the crank all day.

Good luck on your adventure!

sik-rod-dog

iTrader: (1)

as cheap (and reliable) as possible.
these words should never be used together lol
when u wana play with the big boy ur goin to have to pay$$$
500 hp on a budget is posible not 800 hp involves more cash not" as cheap (and reliable) as possible"

smokeshow

iTrader: (16)

How does the saying go? Power, reliability, cost...choose two. I think that's it. Although LS engines seem to disprove that saying to an extent, it stays about 95% true lol. With 800 on the ground from a 5.3, you're going to give up some of that reliability factor. There's no question about it.

01silvy

^^^^^ i agree.. and whether its the 5.3 or the 6.0 800hp aint gonna have too good of mpg.. if you go the stroker route, you'll lose reliability to a certain extent.. I would say go with the 6.0 and forget the stroker idea, i would maybe just bore it alittle.. All forged internals and with a spot on tune you would have a reliable DD.

TURBHOE

iTrader: (4)

what year 5.3? newer ones have bigger rods. i say go 5.3 make sure its in good condition and if anything throw in some wiseco stock size replacement pistons. they are just a touch over bore. some good heads and a cam then a good size turbo. thing about turbo's, when your not in boost its like n/a depending on load. mine gets the same mpg now as it did when i got it except for WOT then the dic reads 1-2mpg . i'm close to the 700awhp mark in a 6020lb tahoe. your trans should be your biggest concern. you should run low boost on the street day in and out and have a switch or controller for high boost for when you really need it. and tune tune tune!!!!! when it comes to tuning, fuel system and monitering equipement don't cheap out. those are the life blood to keeping things alive.

you don't NEED a stroker to make power and you don't have to rev to the moon either, just parts that get along well with each other.

iregret

iTrader: (4)

I'm not sold on going with a stroker kit. I was merely stating they exist.

I guess what kind of bothers me is how much the forged bottom end costs. It seems like if you're going to be spending 1500.00 or more on forged parts, it might be wise to go ahead and do so on a 6.0L. Ya know?

When I said 800hp, I meant at the crank. I brought up turbo because I didn't think at that horsepower level it would be wise to go supercharged, but I'm open to suggestions. I'm trying to strategize a long term goal so I can be on the lookout for parts.

I just want to be wise with my money, that's all. Oh, it's going in a 2000 Silverado. 4L80E, NP149, SC3000 stall, 3.73's

02'Z71ONDUBZ'

iTrader: (8)

The best way you could spend your money would be on a 6.0 and a turbo kit, forget the P1 and 5.3. 408 out of an LM7 is a terrible idea. When you want to forge it, punch it out to a 370 and run forged pistons and rods with a stock crank, ARP rod bolts and head studs, LS9 gaskets. Should be able to boost that setup to around 1000hp

NemeSS

iTrader: (123)

The 5.3 is more than capable of that goal. I'm at the point now that I prefer the 4.8/5.3 motors for turbo builds.

53RUSSELL

iTrader: (9)

i made 520hp/580rw to rear tires on 10lb of boost on a 5.3 motor way over a 100k.