5.3/6.0 capabilities

[softballnrd27]

What has to be done to an iron LS block in order for it to handle 700-800hp with boost? Which block is better 5.3 or 6.0 for a turbo build? Is it more cost effective to just get the LSX block from GMPP? I am planning my build for my LS swap so I can order parts while I am deployed. I want a turbo LS under the hood that will last and be powerful as hell.

[BR3W CITY]

the 6.0 is going to give you the extra displacement, so if your spending the money you might as well take the few extra cubes.

Probably want to go with forged pistons and a good rod (h-beams?), and stuff like upgraded rod bolts. I'm not sure at what hp rating you start to actually worry about the block itself failing.

[softballnrd27]

I plan to go all forged on the rotating assy, I just want to know if I stay stock what block is better suited for my power/boost level wishes.

[85burb]

IF you got the money i would get the LSX block. Capable of holding 2500 HP. If you will be getting new internals and heads it would not be a hole lot more. And you can bore and stroke it all the way to 511 cubes. It also has 6 bolt heads. I think the 6.0 cylinder walls are too thin to bore out too much.

[Super73]

An iron block will hold that power all day long. There are many 5.7 Alum blocks well over that number in power cars. Look at guys like Harlan and a few others there. Over 1000rwhp with a stock crank and stock alum 5.7 block 6 years ago.

[silverspeed04]

You should be fine with the stock block. A lot is going to depend on how much boost you want to get to that HP or higher HP with lower boost. I would say go with the 6.0, but I am biast because I enjoy the one in my daily. Just remember, too much internal combustion and it turns external.

Be safe Marine. Its suckin right now over here for everybody. Look forward to seeing this when you get back.

[swb85]

Like Super said, the factory LS blocks are tough as hell. In fact (if you have a good tune) the factory guts can take a beating too. We have a local guy that runs a bone stock 150k mile junkyard 5.3 in a featherweight mazda rx7. Only parts that aren't stock are the cam/pushrods/head studs & head gaskets. He runs a single turbo w/e85 and makes close to 700rwhp through a th400, big converter, 9" rear with 32x17 hoosier qtp's. Car runs 8.90's at 154mph in the quarter.

[Shon]

Local is making 900+ at the wheels with iron block with a 91mm turbo.
TSP has some rotating assemblies on clearance for $1850, might be worth looking at all over 400 cubes...

[softballnrd27]

I just want to get it right the 1st time and since this will be my 1st high hp/forced induction motor I want to make 100% sure I am getting the right parts.

[ripdog28]

Just be careful with the power. Cage and all at that HP level. Im just under 600 and it scares the hell out of me when i hit it. Never owned anything over 325hp until this. Just dont want to see something bad happen to you after getting out of the hell hole.

[BR3W CITY]

^you saying that me running a 400+ hp motor on manual disc brakes is a bad idea

[softballnrd27]

The truck will be "built" to handle that power before I put it in there. I am going to rebuild the front suspension and upgrade the braking and add a cage as well. I am also going to install a trailing arm rear suspension prior to the swap.

[209jose71]

i have been wanting to turbo my truck to i was wondering the same thing about the 5.3 vs 6.0 to turbo

[Shon]

Either will work, heck the 4.8s can go fast too.
good thing about the 4.8 and 5.3s they are cheap and plentiful compared to the 6.0...I can not find a 6.0 in my area right now.....

[softballnrd27]

As it stands right now I am going ot buy a 100% complete running 6.0 to put in the truck to get rid of the tired 305. I am going to buy a 6.0l longblock to use as the turbo build so I can have a running and driving truck while the motor is built. On another note, I might have found my son's project truck for us to build on until he turns 16. Gives us 6 years, and he wants it be flat black like mine!! I love that little guy!!!

[68 c10 ls2]

Just my 2 cents. 6.0 all day long unless you have big cash to buy an LSX block. I know your going to run a turbo but check out the Magneson Supercharges web site. They punch a 6.0(364ci) out to a 408ci running 10psi on 92 octane and make 950hp at the flywheel. I am running a stock 6.0 with 15psi of boost on E85 and "so far" its holding together! :-).