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ClayA, ASE Certified Technician
Category: Chevy
Satisfied Customers: 116
Experience:  Ten years experience, ASE Master and Advanced Level Specialist certifications. 2006 Winner National Ford/AAA Student Auto Skills
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97-2002 corvette: what is difference between a chevrolet ls6

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what is difference between a chevrolet ls6 block from 1997-2002 and one from 2005-2013 ?
As far a my books show the LS6 blocks were the same from 2001-2006. That was when they were produced. The LS6 engine was introduced to replace the LS1 engine. The block itself shares its basic block architecture with the LS1 but other changes were made to the design such as windows cast into the block between cylinders, improved main web strength and bay to bay breathing. The LS6 was later replaced by the LS2 sometime in 2006.

Why are you needing this information? I could maybe help a little more if I knew what you were using this information for.
Customer: replied 4 years ago.

I bought a new Ls6 engine block on ebay to rebuild as a spare for my 1971 firebird , has been LSX'ed of course but dont know the year of the block . So now im stumped buying parts for it online it does have a stamp of 12561168 on it tho. i dont know if its the older or newer style ls6.

There was only on style of LS6 block that I know of and it was stamped 12561168.

The LS1 and LS6 use all of the same parts. The only difference was that the LS6 engine came with different heads, cam, and intake than the LS1. However, all of these parts would interchange.

What kind of parts are you looking for and I can help you?

The stock bore is 3.898 if you are looking for pistons.
Customer: replied 4 years ago.

entire rotating assembly to start with , this would be a stock bore aluminum engine . Hoping to find a website that will sell as a set prebalanced as i dont have a good machine shop locally .

Okay, we can find you a rotating assembly no problem. However, I need to know the answer to some questions before I send you to a website to order parts. We need to know the total anticipated engine build.

  1. Is this going to be a stock rebuild or performance? I am guessing performance.
  2. What are you anticipated power goals? How much horse power would you like to make?
  3. Will you be boosting or using nitrous?
  4. What will this car be used for; cruiser, hot rod/street machine, or race car?
  5. Do you have a compression ratio in mind and do you want to use pump gas?
  6. Do you have heads and cam already picked out?
  7. Finally, what is your budget? This is the biggest limiting factor.

I would like to help you with a total car build plan. This usually works out better than just throwing parts together and hoping for the best.

Customer: replied 4 years ago.

1. performance 2. 500-550 3.possible procharger 4. street machine 5. 9.5.1 compression is prefered by procharger techs. 6. no but wanted a cam of around 600 lift . 7. like to keep internal parts around $7,000 . I already have two FAST intakes and two 92 mm throttle bodies new , one cable driven one electronic . This wont be much more than my car has now 472 rwhp - 456lbs. torque, N/A on the dyno

Okay, $7000 for internals should not be a problem but will cut it close with a good rotating assembly and valve train. The fast intake and throttle body will make awesome horsepower. So you are already good on that end of things. 550 HP+ is no problem with a 383 Ci LS engine and a procharger. When you are boosted, your head selection is not as critical as when you are NA. So a good stock set of LS6 243 casting heads will work great for what you want and are not very expensive. However, a good set of heads can and will make more power but might put you over budget.

Here are my recommendations for companies and parts below.

For a rotating assembly I would recommend Texas Speed. Below are two options. They have a 347 CI or 383 CI rotating assembly kit. They are great guys who will work with you to get you exactly what you need.

347 Rotating Assembly
383 Rotating Assembly

As for as cam choice I recommend you call Geoff at Engine Power Systems. Tell him what you want and what you plan on doing. He will custom spec. a cam grind that will work for your car and your needs. Not just a cam pulled off a shelf but one that does what you want. I run a cam from him in my daily driver and love it. I make 430rwhp in a Silverado Z71 with one of his cams: 226/230 .598 .601. His company has great friendly customer service and are very honest with expectations on driveability and horsepower output.

Here is EPS website

If you have any further questions or need any help. Just let me know.
ClayA and 7 other Chevy Specialists are ready to help you
Customer: replied 4 years ago.

Clay you are awesome guy thanks for the tips, you've been real helpful thanks for the extra effort also. Get back to you guys if i run into any more bumps . Laughing


I'm just following up with you to see how everything is going or if you need any further help.

Did my answer help?
If it did please click the "Accept" button.

Let me know,
Customer: replied 4 years ago.

Awesome info the guys at texas speed hooked me up, for around 9k bucks but i wanted the best parts they had ;) . Everything is set to go, the main differences in these engines are the new models have a 58 tooth reluctor wheel and a vented valley pan cover, as to the older ones where nonvented and 24x reluctor wheel which mine will have. Also found a really awesome setup for the front drive system , , I purchased it today . you were very helpful and thanx alot bud for the good hookups.

Those are all parts changes on the LS6 engine vs. the LS1. However, the block itself is the same on all LS6 engines. The crankshafts did change to the 58 tooth reluctor wheel for a higher resolution signal over the 24 tooth reluctor wheel. Then they changed the PCV system from the valve cover type PCV to a vented valley cover. All of this can be bolted on any LS motor. I just stays the same as what the car already has usually. Make hook ups to computer harness and vacuum lines easier.

That front drive system is amazing. Thanks for sharing.

If you don't mind it would be awesome for you to post your HP numbers after you get it together.
Customer: replied 4 years ago.

thanx for the extra info, im also researching a catch can. Thanx for the extra info, im also researching a catch can.I'm not sure if it's a good idea or even how to install it , haven't found anything yet. Doesn't look like it would hurt anything. Sure thing i'll keep you posted on the build, after speaking with you i don't wanna talk to anyone else, you seem to explain things better for me. Be awesome even if this site was a pay site but just Q&A for gear heads with more of a facebook feel I could ask for you personally haha, take care bud, keep building them ponies ;) .

A catch can is a good idea on a boosted motor. It installs on the PCV hose and keeps you from getting oil into the intake. Very easy and simple to install. Below is the install of a good style can on a LS6.

Link Here
ClayA and 7 other Chevy Specialists are ready to help you
Customer: replied 4 years ago.

Thanks just purchased one even tho its not boosted for 50 bucks it's well worth it to help protect it, i also bought a breather style billet oil cap. Also i've always used mobil 1 full synthetic in everything i own. i bought a bottle of comp cams breakin oil additive and 2 cases of mobil 1 15w-50 to run in it after breakin. I wanted the protection of the higher viscosity. What do you think?

It will work just fine.