Sabes

Hi! Im from Wisconsin first off. I just disassembled what im pretty sure is a gen3 lm7. I bought this engine as a cheap swap/build for my 6banger mustang which I plan on pairing with a t56. This will be my summer cruiser/ take her to the strip car.

Next for those who may have to feel like saying it... There are hundreds of threads, hundreds... Been searching for a months since I bought my lm7 and found im not very good at remembering or organizing online info that's why my post will exist... And in general am not 100% in what to buy.

For my build I am looking to push 500-600hp with the help of a turbo, probably hx55 for size availability and cheapness. What do you guys think?
First big question in which I have no solid answer for, will my stock crank hold up to hp or even pair with a t56?
I wanna replace most if not all internal parts. Bearings, connecting rods, pistons, rings, push rods, lifters, rocker arms, springs, etc. what brand do yall buy? Do you guys back up stock parts?
I'm reusing my 862 heads and probably stock truck intake since I have truck pulleys. Hoping everything clears 😅
Now y'all wanna kno my budget lol lets just say I wanna keep it low yet reliable but withought figuring the trans $2000ish

VandykeT/A

The budget isn’t going to work. To reliably make that power your gonna need forged rods and pistons. Stock crank is fine. Turbo kit and a cam swap should come close to 550-600 but the expense of injectors fuel system tuning not to mention the turbo set up its self is gonna be way more than 2k. We had a cam only LS1 vette with twins make a little over 600 on 11 psi

ss.slp.ls1

iTrader: (36)

Glad you are planning on replacing the internals of the shortblock. I would reach out to one of the vendors on here and discuss your build with them to ascertain exactly which rods, pistons, etc you will be using. Since you are getting new pistons, you can choose the appropriate amount of dish to target a low compression. If you were staying with the stock internals, I was going to recommend picking up a set of 317 heads to lower your compression. The same vendor should be able to recommend a nice boost oriented camshaft, or you can look to some of the forced induction threads to narrow down the choices. As stated, your stock crank will hold just fine.

P.S. Considering your budget, you might want to just keep the 5.3 unaltered, slap on a turbo set up, upgrade your fuel system (pump & injectors), and tune the PCM. Those steps alone will eat up your budget quickly.

nine8ss

iTrader: (5)

600hp with a budget of $2k is very impractical. A used twin turbo kit($1500-$2000 or more), without supporting mods, might get you in the low/mid 500's if your base is a SBE LM7.

Sabes

Sorry i didn't really mention I have a turbo kit minus turbo and all engine gaskets already. That's the price im "shooting" for in building basically a long block, and im not looking for the most expensive parts so i figured that should get me in the ballpark. Bolt ons come after this price.
if you guys think i can get away with using stock parts with this gen engine I will. I just want the engine to last. The parts are very clean other then the ends of the push rods.

Sabes

Awesome info. I will definitely talk to a vendor. I will have to figure out that feature on this forum. Since i am just finding out about vendors is there any you recommend?

ss.slp.ls1

iTrader: (36)

Since you already have a turbo kit, I would round out your parts gathering with a turbo, injectors, and fuel system before I bought anything else. Once you have everything necessary to run boost (also budget for the dyno tune), then spend your money on the bottom end. That way if your money dries up, you can always throw everything together on the stock bottom end and run a modest amount of boost on a conservative tune for a while and you could swap in a forged bottom end in the future. Now that is just my opinion of course. Others might say to build your bottom end first and then when money allows to throw on the completed turbo kit and the required parts.

HappySalesman

iTrader: (3)

Even with already having the turbo kit (sans turbo) I think 2k isn't really attainable, unless you're able to get some parts for CHEAP. Injectors and pump alone are going to set you back roughly 400. Add another 400 for a cam. The smaller internal parts alone are going to be close to 750. Figure 200 for rockers, 300 for good bearings, rings will be 70, lifters 170. Right there you're at 1550 and you haven't included the cost of a tune (500ish) or the turbo itself.

your heads aren't going to support 600hp well either, especially not with a stock truck intake. The bottom end can handle up to 600, but make sure everything is in good condition, and set your ring gaps properly. There's an article floating around the internet (I think it was super chevy) about how much boost an SBE 6.0 could take. Think they ran it up to like 1100hp before a lifter failed. you'll want to invest in good rod bolts, which means resizing them. forged bottom end parts really are the most reliable way to go however.

personally, i'm a fan of do it once, do it right. You're gonna have extra work already swapping it into a mustang, why add more having to tear down the motor multiple times and piecemeal it together? I'd spend a bit more time saving up money, get a better set of heads (like 243's) and an LS6 intake, and make your goal more attainable.

Sabes

Sorry for the confusion I keep thinking I'm getting my build across. The 2k is for engine internals not injectors, turbo, pump etc. There is another stash of money for that lol. The few other questions I asked were also things I was unsure of and the heads are getting rebuilt (will the heads still not work rebuilt?) Also I already know what I want for "bolt ons". Your guestimates for "1550" actually saves me $450 on what I have set aside for this portionn of my build(which would give me money for better heads? Lol). I only want to build it once so I'm looking for parts people say they stand behind

nine8ss

iTrader: (5)

It is tough to figure out what it is you really want.

Can you summarize into one post by chance?

"Rebuilt" heads are just stock heads that are shiny and clean. Put that rebuild money into a quality set of heads.

HappySalesman

iTrader: (3)

What nine said. The 862 heads stock don't flow well enough to get to 600hp. Stock 243s might get you close, but you'll honestly be best off porting them.

Sabes

Ok I can do this lol. So to keep it simple lets start with I have a bear block fully torn down. Aside I have all stock parts all looks good except scratched cam and worn push rods. With this block i am looking to achieve 500hp if I can up boost 600hp max if 600 is attainable with reliabilty if not 500hp is good.
For just the block portion of my build I am looking to drop $2000 this money will afford me all parts to build a reliable long block; bearings, connecting rods, piston, piston rings, push rods, valves, valve springs, cam, etc. I already have all gaskets and seals. What parts will I not need to buy lol and what brands does everyone like that will not bend or explode. Also what upgrades will help me out I've heard tri-union rockers?
For the heads I guess I will just have to find some on Craigslist or at a junkyard.
For the intake i assume my truck intake will not work with the heads? This also puts me in a position of needing a new belt drive setup which i did not figure into cost because everything would have cleared but that's to worry about a different day.

HappySalesman

iTrader: (3)

This is what I would do if i were going this route...

Forged pistons: 700 (wiseco is a good brand, mahle as well)
H-beam rods: 4-500 (Scat is a common choice)
bearings: 250 (Clevite is a common choice)
Upgraded oil pump: 250 (Ported LS6 or melling)
Buy a set of stage 1 243 heads from Texas Speed: 1450 (Fully assembled head with springs and valves)
Stock rockers with trunion upgrade: 250 (keep in mind these will scrub the hell out of the valve guides above .600 lift, so you may want to consider roller rockers)
Pushrods: 200
Lifters: 220 (Don't use LS7 lifters, go with Morel 5315)
Cam: 400
Used LS6 intake: 3-400. (you'll see better performance with a Fast 92, but significantly more expensive)

The truck intake will fit, but I personally wouldn't run it. It's designed for trucks, they make torque down low, but sacrifice power up high. Whereas the car intakes are more designed for performance.