blackz03

Hey guys, I’ve been toying with the idea of swapping a new GM 427 570hp crate engine in my 02 Z! I think it would be great to have a factory built engine with a warranty that is reliable and makes great power in a 3100lb car! I drive the car 4-5 days a week in the summer so having a built LS6 might not be as reliable as having a factory built 427 with that kind of power. I’m thinking kooks headers/high flow cats and a good clutch and this thing will be a smooth rocket! Tires obviously will be needed, but at $12,700 for the engine I think it’s a cool idea! Any thoughts/opinions are greatly appreciated especially if you have a 427 in your C5!

Thanks!

Boeuf

I don't have a clue what would be involved in that swap but I bet it would be freakin' awesome and fast as hell.

I love NA performance especially if you plan on doing any road racing.

rustyguns

people do it all the time! go for it, makes the car a magic machine!

Tusc

These cars can be driven daily year-round without issue. I have dailied my first two C5s at one time or another, and the first '00 was driven off the lot as such. Changing things up sometimes leads to reliability issues - not with the product itself, but with things you have personally altered to make them work. Be careful and you can avoid any such issues.

Now.... 427.... as in the LS7 with the titanium rod coating which wear off and see the rods fail if you run it too hot? That same LS7 which drops valves? The one GM quietly and eagerly ran away from as an entire platform? Notice, if you will, that the ZR1 and all newer Corvettes are not based on the awesome 427 but on evolutions of the LS3. Owners with warranties were glad when GM came out with the "wiggle test" to see if their heads were good or needed to be replaced. When that test saw too many positives, GM quietly removed it saying it was not accurate enough. SO... google whatever it is you are buying. If this is a new wholly different 427 design, sweet. And even if it is the same LS7... no biggie... the problems listed don't happen to everyone. But it is good to be aware before you drop the debit card on it.

I don't know what backing TSP offers, but for the same ballpark money they offer some engines with a lot of upgraded internals. You can get an LS3 based 427 from them here: TSP LS3 427

Or if you have a machinist who builds a LOT of successful LSs, you pay them to do the work and you can source FAR BETTER engine parts for the same money. That is the route I took as I have only built two engines in my life and they were in the 420 rwhp range. There was no way after a hiadus of a decade that I was going to trust my own hands on a 750 to xxxx+ rw build.

USAZR1

I would add a supercharger to my modified LS6, before spending $15K on an LS7 swap, but that's just me, though.

blackz03

This is the engine I was thinking of. I haven’t done enough research yet to see if they got rid of all of the original 427 issues, but I’m assuming they did. https://www.ebay.com/itm/New-Chevrol...-/303605721477

Old School

I like the idea of a LS7 powered C5z but in terms of money and time spent and resale, I would sell your C5z and use that money plus the (over) 12 grand towards a C6z. That's just me.
I like USAZR1s idea of supercharging though unless there is a problem with your LS6 and that's why you're looking to replace it.

blackz03

I have had boosted cars before and they are fun but I’ve always wanted heads/cam or 427 C5 Z! I drive it a good amount so I figured a stock NEW 427 with headers and possibly a cam would be reliable and more than enough power in a C5Z. I’ve been looking at TSP 427s and there heads/cam packages as well, definitely great stuff, but this new 570hp ls7 popped up and got me thinking!

rustyguns

Texas speed rocks!

~Josh

I’ve owned a C6z and the LS7 was an awesome engine to say the least.

That said, every one will eventually have the coatings wear off the Ti rods, only a matter of time. Up to the end of production they never fixed the valve issues, and for the money you can build something much better.

Personally I say you should get your cam/valve train capable of 7k rpm, then boost your LS6 even on low boost you’d surpass anything the LS7 can make NA.

$12k buys a lot of stuff including clutch, full exhaust, maybe diff with a wavetrac (google it) posi, etc if you take the boosted LS6 path.

jmbbluevette

i have a 2003 black Z06 with an LS7. The NA LS7 is good for about 560 rwhp and 550 rwtq. Had an 01 with boost with about the same hp and a lot less torque. Nothing compares in my book with my NA LS7 performance. The 01 had a 3:90 rear end while the 03 has a 3:73 rear end. The LS7 I got has a custom dry sump, and it is supported by Mantic 9000 dual disk clutch, ARH 1 7/8 headers with high flow cats, TR6060 transmission with hardened main output shaft, 3:73 rear end with hardened output shaft, C6 Z06 calipers, Coleman two piece rotors, and Dewitts radiator and oil cooler. The engine now has over 40,000 miles. It is a beast that always put a smile in my face when I drive my Vette. If that is what you want, then that is the way you should go. You definitely want a good set of rear tires. I currently run 315/30/18 in the rear. The tires are BFG Rival S. I can spin those tires in any gear. Good luck with your decision. Remember that it is what makes you happy in the long run. More if you are planning to keep your Vette.

rustyguns

The Gm engine is really good. Personally if I had an LS7 I would lower the rev limiter to 6500 rpm and if your worried about the valve train upgrade it! This guy has good tips:First, bearings. You do not have to worry about bearing failure as long as you ensure the oil is hot before you beat on the car. Back out of the garage and start doing burnouts and brodies, you are asking for it in any car, Z06 included.

Second, valves. It is not the hollow-stemmed voodoo valves in the exhaust that are causing these failures. The problem is with the guides. Guys that went to stainless solid valves, but did not change the valve guides because their cars had low miles, are beginning to see failures of the solid valves. The guys that went to bronze guides, be it solid or hollow stemmed exhaust valves are still driving and smiling.

https://www.arizonacorvetteenthusias...train-failure/

If you are buying a C6 Z06 that has stock valve guides, do yourself a favor and have the heads reworked. It does cost, but the peace of mind from being able to enjoy the car and not worry about failure far outweigh the monetary expense you will incur.

Tusc

So non-LS7 427, or boost. Both solid options. Both will require supporting mods. Both will be fun with only minor headaches.

1999corvettels1

About a month ago I noticed the crate LS7 dropped down to $10,900.00, wasn't looking at LS7 but LS3 for my 1965 C10 truck.

Started thinking what LS7 in old truck would be like, but the valve guide issues scare me, also I bet there is zero warranty putting it in a truck, and even a C5 unless a dealer installs it in a C5.

Sounds fun though!

dskinsler83

Id get something other than an LS7. 12k + is half the value of a PRISTINE C5. Not to mention the things needed to run that 58 tooth reluctor etc in the car. The MM12 is supposedly weaker than the MN6 but either one would need beefing up to handle that kind of everyday power and torque along with the rear end and torque tube. Buy a C6Z or build something better with aftermarket heads. texas speed has good stuff and would be a better build. Plus it can have a 24 tooth reluctor and then all ya need is the cam, knock, and tb harness adapters.

Tusc

I haven't checked the posting, but I wonder if the LS7 as a crate engine would have the option of 24 vs 58 tooth reluctors. If not, it is only a $250 box from LPE to convert the signal.

turabo87

For 570HP at crank I wouldn't bother with a crate LS7, mostly due to cost. HCI full effort NA LS1 stock bottom end builds can easily (and dare I say reliably if you do it correctly) surpass 530-540 HP, which equates rougly to 440-450WHP. Now, for more of a full effort HCI 600+WHP NA LS7 build, now that's a different story if you're willing to spend the money. I'm a bang for the buck kinda guy, so if I had more means and I wanted more cubic inch, I'd probably go the 383 stroker route on a junkyard 5.3 or good used LS1/LS6, and build it right.

PS: I am one of those that daily their HCI C5, been dailying it for last 1.5 years, and I've been graced not having to call a tow truck once. I didn't cheap out in the process and did my homework, but it was nowhere near 12k, probably half of that.

Z06_NV

Well I own a Forged built B/B 12.5 to 1 LS7 in my 02 c5 vert. I bought it from the original owner last year and she is fun. Makes over 605whp Na on E85. on a conservative tune from Dr.Phil. The engine runs great and screams at 7400rpm. The original owner built the engine to handle a 300 shot n02, which was never installed, and i don't think i ever will do that. I would like to add a 3 inch axle back exhaust, instead of the 2.5 z06 titanium and a more aggressive tune and shoot for over 650whp Na.

LowcountryVette

For those who aren’t aware this is gm’s new ls7 based crate engine. The primary changes being a wet sump instead of dry sump to make swaps easier, and a different cam. See below


Compared to the production LS7 crate engine assembly, the LS427/570 features an F-body aluminum oil pan and a specific wet-sump oil pump. Additional engine highlights include:

• Unique high-lift hydraulic roller camshaft with 0.591-inch intake/0.590-inch exhaust lift; 227-degree intake/242-degree exhaust duration; and a lobe separation angle of 116 degrees
• Unique high-rate valve springs
• Camaro fifth-generation Z/28 exhaust manifolds
• Low-profile LS7 EFI intake manifold with fuel rails, injectors and throttle body installed
• Robust LS7 rotating assembly featuring a forged steel crankshaft and titanium connecting rods
• CNC-ported cylinder heads featuring 2.20-inch titanium intake valves and 1.61-inch sodium-filled exhaust valves
• Fourteen-inch Camaro Z/28 168-tooth manual transmission flywheel
• Must be used with LS427/570 Engine Controller P/N 19420000 (sold separately)
• Chevrolet Performance recommends Mobil 1 15W50 fully synthetic motor oil to be used with the engine

LowcountryVette

So on top of being overpriced, I think it will have the same issues the production ls7’s did.
A better option would probably be to find a pulled ls7 that already has go fast parts and had common failures addressed