LT1PWRD

iTrader: (2)

Planning a junkyard truck LS turbo build and i'm wondering if the the aluminum blocks(LH6/LC9) can handle the same boost\HP that the cast(LY5\LMG) blocks can. Are the sleeves as thick as the cast iron blocks?
Thanks

NightmareTA

iTrader: (20)

Don't quote me on this because I'm not truly 100% sure, but I would have to assume that stock for stock, the iron block 5.3 will handle a bit more than the aluminum version. Only thing that would lead me to believe that is because 99% of the JY truck engine turbo builds are with iron blocks. Got to be a reason for that I'm assuming. Unless your overly concerned about weight, I'd go for the iron block.

Sarg

iTrader: (6)

I was under the impression that Skinnies was running an aluminum block and doing just fine at 800 hp and 1200 torque.

chuntington101

Asumming you can keep the heads down then I would guess that the 5.3 ally blocks can take higher peak cylinder presures than the LS1 ally block thanks to the thicker cylinder walls. probably best to talk to your engine builder about it though.

Chris.

LT1PWRD

iTrader: (2)

Do the iron blocks have beefier decks as well as cylinder walls? And what year 5.3's are better,3rd or 4th gen? Can i get around the VVT in the 4th gen as far as using earlier cams and timing chains or should i just get a gen3 ? I was absolutely blown away (no pun intended,lol) when i read Hot Rod Mag's article (sep.2011) Big Bang Theory! It went over 1200HP,didnt blow and ended up being a 4.8! Granted they did heads,cam and ring gap but still ! Thats amazing and goes to show you (again) how great these LS engines are!
Not overly concerned about weight but it's always nice to go lighter if it can hold the same power. I will always choose durability over saving a few pounds.

Sarg

iTrader: (6)

The only thing I am curious about is which aluminum blocks have the LS1 bellhousing pattern and which have the FWD bolt pattern out of the cars and how to tell the difference in them. Or are people just getting the FWD ones and using an adapter plate?

LT1PWRD

iTrader: (2)

Hey Sarg,i got this from Wikepedia. Alot of good info on here for all the LS generations

The LS4 is a 5,328 cc (5.328 L; 325.1 cu in) version of the Generation IV block. Though it has the same displacement as the Vortec 5300 LY5, it features an aluminum block instead of iron, and it uses the same cylinder head as the Generation III LS6 engine. The bellhousing bolt pattern differs from the rear-wheel drive blocks.
This engine is adapted for transverse front-wheel drive applications. According to GM, "The crankshaft is shortened 13 mm – 3 mm at the flywheel end and 10 mm at the accessory drive end – to reduce the length of the engine compared to the 6.0L. All accessories are driven by a single serpentine belt to save space. The water pump is mounted remotely with an elongated pump manifold that connects it to the coolant passages. Revised oil pan baffles, or windage trays, are incorporated into the LS4 to ensure that the oil sump stays loaded during high-g cornering."[6] Active Fuel Management is also used. Output of this version is 303 hp (226 kW)/300 hp on LaCrosse Super and 323 lb·ft (438 N·m).
Applications:
2006–2009 Chevrolet Impala SS
2006–2007 Chevrolet Monte Carlo SS
2005–2008 Pontiac Grand Prix GXP
2008–2009 Buick LaCrosse Super

Sarg

iTrader: (6)

Ya, I knew the blocks were different, just not sure if people are using them with an adapter or if they were getting the aluminum truck 5.3's. But thanks for posting up that information!

stock48

iTrader: (17)

Yea they're crazy thick you would blow the heads and main caps off well before you split one of those cyls. The cyl would also stay true under big power vs the crappy egg shaped iron lq4 cyls.

JoeyGC5

iTrader: (24)

You gonna try another small motor?

99Ls1fever

iTrader: (3)

There is one local guy running 1300hp on a stock 5.3 block and crack here in colorado... 104mm turbo I believe, 5.3 in a gutted 70 nova

MaxxMitchell

iTrader: (15)

Most people run the iron 5.3s due to cost. Both blocks will support well beyond what the internals will, and in my opinion more power then a 4 bolt head can hold with out o-rings