I have to replace my 2003 ZO6 LS6 (oil filter came loose and dropped 6 quarts seizing the engine). If i do this, what is the best course of action? Should I get a swap or what can I do so I can get more horsepower to the car? Is it possible to insert an LS3 or make the LS6 engine better for increased horsepower?

 

 

Moved to C5 Tech.

 

One option is to buy an 02 to 04 LS1 short block from a vette or one from an fbody with the casting number of the LS6 block. They are identical to an LS6 short block from a Z06 but usually priced cheaper. Transfer your heads and other parts, with your choice of cam. Build up the engine yourself, and then have a shop install along with a new clutch.
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Used ls6 would be the way I’d suggest...

I think the reluctor wheel or something like that from a ls3 makes the swap you mentioned a pain in the butt...

Save whatever parts you can off your motor that didn’t get trashed ie accessories...

If you love the car ...plan on keeping a really long time...you can throw in a built motor pretty easy but as mentioned you’d be upside down..

A crate motor isn’t too bad and does come from GM with a warranty which is nice...

Low mileage ls6 would be what I’d do in hindsight.

I had a modded c5 z06 that’s motor blew...I sold the car without a working engine....the same day...I took the value of the car at the time..subtracted 7 grand for a replacement engine and called it a day.

I called up kerbeck and that day drove 4 hours in a rental car....with a check to buy a new c6 z51 ls3 m6 with npp...

The ls3 is a stout motor and as long as it’s a crate motor I’d imagine that reluctor wheel issue if that’s even what it’s called....(sorry it’s a long time maybe 10 or 11 years)

Fwiw...to this day I still miss my torch red c5z06...

Btw I have put a remarkable 122k miles on that black c6 z51 m6 ls3 and it’s been the most reliable car I’ve ever owned and I still love it....(but the c5 z06 really reminded me of a raw race car like driving experience and that’s really a timeless experience..

The c5 z06 really is a wonderful sports car...

Check out your options...with either preowned ls6 or a few easy choices of built motors or a crate motor ...

Decide how long you want to keep your z06...

That’s really your answer on which way to proceed.

Sorry this happened to you.

I remember the headache I had when at about 65k Miles the motor went out...

Btw three months earlier I blew the differential, the guibos and had some work done in the transmission and possibly the clutch..

I dropped a ton of cash three months earlier fixing those things and then 3 months later...and I kid you not...100 yards away from where the trans issue stopped the vehicle...the motor blew...

I got double whammied within a three month period and walked away from the car without the motor...

Miserary loves company so I hope my worse experience at the time (a decade ago)helps you realize it happens to many of us...

Btw I wasn’t beating the car...it just happened...

The fun part of the story is a car full of college girls as well as cool guy in a motorcycle helped me push the car from the center lane of a four lane highway to the side of the roads..so I wouldnt get run over...as I had my handicapped kid in the car with me ...

Make lemonade out of lemons my friend,

Best of luck

 

The easiest swap would be another LS1/LS6 (Gen3) or Gen 3 iron block. The LS6 block had some windows in the block to improve windage which LS1s did not. The average street car will not notice the change.

LPE has a good list of motors and their sensors in the instructions of their converter box. Gen4 motors will require a knock sensor, cam position sensor relocation harness, and possibly a converter box. LS3s require some modification to the motor mount. Knock sensors will have to be retuned with the relocation to the side of block which is required with Gen4 motors. LS2/3/7 are Gen 4 motors.

https://www.lingenfelter.com/PDFdown...L460065397.pdf

A good LS3/L92 swap topic:
https://ls1tech.com/forums/conversio...3-into-c5.html

What are your goals for the car. Is this a street car, any plans for a power adder, any on track HPDE time?

 

LS6 blocks were used in LS1 motors. You can swap the cam and heads to create a LS6. 04 GTO motors work as well.

I went with a CTS-V LS6 short block.

Later LS6 blocks had the new heads bolt

https://ls1tech.com/forums/generatio...lt-length.html

 

Buy a crate engine LS1 short block(no heads) work your heads(seals, valve job, mill and springs) put in a cam, headers etc and put it back together.

No reason to drive yourself nuts over an LS6 block, not worth it.

 

This sounds like the best way to go cost/performance wise.