LS3 / LS7 top end ( heads / fast 102mm ) ?
Thread Starter
Burning Brakes
Joined: Dec 2004
Posts: 1,149
Likes: 143
LS3 / LS7 top end ( heads / fast 102mm ) ?
I am going to be starting with a clean slate on a 2004 Z06.
Should I bother modding the stock LS6 or go straight for a LS3 conversion so I can take advantage of all the LS3/LS7 top end components ?
If I go with a 6.2 aluminum block or a 427 sleeved LS2 , will these always be limited by the weaker top end components ?
I have not spent a dime yet. I dont want to dump money into a 5.7 when it will never provide the power vs driveability of a LS3/LS7 combo.
My goals are 500 - 550 RWHP / 500 RWTQ with a really nice clutch setup and mild manners if I bother spending the money on a 427. I don't mind putting the money into more cubes so I can run a mild cam. If I stick with the 5.7 , probably 440 rwhp / 400 rwtq is all I can see getting and still maintaining good manners correct ?
I dont want to step much past 500 rwtq because I do not want to deal with POS clutch issues.
Any advice
Should I bother modding the stock LS6 or go straight for a LS3 conversion so I can take advantage of all the LS3/LS7 top end components ?
If I go with a 6.2 aluminum block or a 427 sleeved LS2 , will these always be limited by the weaker top end components ?
I have not spent a dime yet. I dont want to dump money into a 5.7 when it will never provide the power vs driveability of a LS3/LS7 combo.
My goals are 500 - 550 RWHP / 500 RWTQ with a really nice clutch setup and mild manners if I bother spending the money on a 427. I don't mind putting the money into more cubes so I can run a mild cam. If I stick with the 5.7 , probably 440 rwhp / 400 rwtq is all I can see getting and still maintaining good manners correct ?
I dont want to step much past 500 rwtq because I do not want to deal with POS clutch issues.
Any advice
Last edited by I brake for nothing; Apr 27, 2009 at 09:39 AM.
Thread Starter
Burning Brakes
Joined: Dec 2004
Posts: 1,149
Likes: 143
What short blocks are compatible with the LS3 / LS7 heads / top end ?
I know you need LS7 heads to run a LS7 manifold and LS3 heads to run a LS3 manifold.
What can you do with a sleeved 5.7 or a 6.0 LS2 / 6.2 ?
Best bang for the buck looks to be a LS3 short block at stock displacement , will I be nickeled and dimed to death on small conversion components ?
I know you need LS7 heads to run a LS7 manifold and LS3 heads to run a LS3 manifold.
What can you do with a sleeved 5.7 or a 6.0 LS2 / 6.2 ?
Best bang for the buck looks to be a LS3 short block at stock displacement , will I be nickeled and dimed to death on small conversion components ?
Former Vendor
Joined: May 2005
Posts: 3,749
Likes: 4
From: Valencia Ca
My goals are 500 - 550 RWHP / 500 RWTQ with a really nice clutch setup and mild manners if I bother spending the money on a 427. I don't mind putting the money into more cubes so I can run a mild cam. If I stick with the 5.7 , probably 440 rwhp / 400 rwtq is all I can see getting and still maintaining good manners correct ?
Yes, call us and we can make this happen
Sleeving a 5.7 is out of the question today - sleeving a 6.0 or 6.2 will yield a great, long sleeve big inch block - add steel caps and it's a stronger, better setup (Darton dry sleeved) than a factory LS7
That depends on where you buy the parts - but reality is that you need mainly GM pieces and if you have a good dealer you will get good pricing.
AMP Racing
Joined: Aug 2006
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From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
Well, I think best bang for buck would be heads and cam on your LS6 - but you wont be much over 450 RWHP if you really want to maintain good street manners.
If you want 500 hp, you will need more cubes. And there are plenty of options, as you have mentioned. Put a 4" crank in an LS3 block and you'll have 414ci. I'm sure there are a number of people that could get 500 hp out of that and still be quite streetable.
Best of success with your project.
If you want 500 hp, you will need more cubes. And there are plenty of options, as you have mentioned. Put a 4" crank in an LS3 block and you'll have 414ci. I'm sure there are a number of people that could get 500 hp out of that and still be quite streetable.
Best of success with your project.
Thread Starter
Burning Brakes
Joined: Dec 2004
Posts: 1,149
Likes: 143
Thanks for the replies 
What do the stock z06 fuel system and pump handle ? I am assuming I will need an injector upgrade with 450 - 500 rwhp ?
What is the sweet spot on these Z06's for power vs expense and reliability ? That is . . . what is the power level that starts breaking drive line parts etc and becomes a hassle ?
I do not want to spend a pile more money chasing 75 more rwhp, only to find I will forever be fixing component failures and be less happy with the car. I dont need to be the fastest thing on earth.
What do the stock z06 fuel system and pump handle ? I am assuming I will need an injector upgrade with 450 - 500 rwhp ?
What is the sweet spot on these Z06's for power vs expense and reliability ? That is . . . what is the power level that starts breaking drive line parts etc and becomes a hassle ?
I do not want to spend a pile more money chasing 75 more rwhp, only to find I will forever be fixing component failures and be less happy with the car. I dont need to be the fastest thing on earth.
