jcollege

iTrader: (2)

Novice question for the details in this thread, but will an LS3 intake, bolt right up to an LS2?

FuzzyLog1c

iTrader: (4)

Yep. 305cc Mast Black Label 6-bolt heads.

Nope. The LS3 uses rectangular ports. The LS2 (and older) use cathedral ports.

Mercier

iTrader: (15)

Yes but requires some ~$600 adapters called LS3-style heads. High bang-for-buck factor in this setup though.

Mercier

iTrader: (15)

Well GD! Make sure you call NASA before you crack it open as those heads might suck satellites out of orbit.

05CTSV

iTrader: (16)

Looks like Mighty Mouse has changed his site around some since I bought it. But it was one of his gen4 pcv cans with 1 fitting being a 3/8 hose and the other being a -10an. I bought the ls head bracket, think it was universal. At the time I had Holley valve covers so I had also used a metco threaded oil cap that had a -10an on it. He now sells that same type of adapter for the threaded valve cover caps. I had to nix the Holley covers in favor of the proform covers I'm running now since they were the only thing that cleared my t&d rockers. The proform has more of an old school oil cap that is just an open hole, the cap just pushes in. I might later see if Mighty Mouse could make me an adapter for these covers. I really did like his can design.

FuzzyLog1c

iTrader: (4)

Not to mention a half-set of offset rockers and a cam designed to take advantage of the different intake/exhaust flow balance. If you don't mill the LS3 heads and relief the pistons, you'll drop from 10.9:1 to 10.4:1 SC as well.

Naf

iTrader: (1)

And intake manifold, and other needed parts. Your $600 heads turns into $1200 quick before you finish.

And you still havent bought a cam...

Mercier

iTrader: (15)

You guys are right but I was coming from a place where a cam would be purchased to compliment ANY upgraded heads..cathedral or rectangle. Occurs to me you can make same/more power with less cam and a cheaper intake and heads.

If one were to upgrade their 243s, they would want to get away from the LS2 intake anyway and get a cam to match. Good 243s fetch $400 so $200 more and you have some LS3s. Call the intake a wash or $100 more fully-loaded, cam is a relative wash. Use your same throttle body. Gaskets, fluids $150 but again, same price for any head swap. Nice LS2 cam can fetch $50 or more. Offset rockers can be bought brand new for $9/ea. so $72.

I may be missing some things but we're still under 500 bones net. And before the "LS3 heads too big for 6.0/4" bore" talk starts, look at the L76. Makes great power with basically same combo and a cam and a few other bolt-ons.

I call that bang for buck.

Naf

iTrader: (1)

You can get more than 500rwhp, with a L76 setup.

Ported heads, ported intake and an awesome clutch will do it.

Had a gto here make 550 at the wheels, but used a vcm cam and otrcai, milled and ported heads and fast intake...

Mercier

iTrader: (15)

That's a big number!

Naf

iTrader: (1)

Its possible, right combo of parts and tune will make it happen...

jmilz28

iTrader: (13)

I don't doubt you personally on this but I think that is an optimistic dyno.

There are a very small handful of legit 6.0/LS3 top end cars at 500 (most are 460ish) and the 6.2 cars in the 525 range, both of those take PROPER heads. Most of the GOOD cam only LS3 cars are 470-480 so to get to 550 with basically heads only is...a tall order. Again, not doubting you personally, but while this is possible, it's not likely. V2s put down 480ish stock and with headers, pulley, HX typically see 550ish at the tires, just for reference.

Mercier

iTrader: (15)

That would require almost 650HP at the crank. 108 HP/liter. I don't doubt that a particular combo of that unicorn "engine built on a Wednesday," a cooperative dyno(uncorrected and in a refrigerator in February), tune that was specifically made to spit out a number (maybe some race gas?) was able to do something like that. Let's say 54x and rounded up too.

My friend's G8 GXP(LS3) with just headers, BTR stage 2 NA cam, valve springs, tune put down 49x at the wheels through an auto in Louisiana humidity and about 96 degrees. He has 12 cubic inches on a L76 - 3%. I've driven the car and we both agree the tune needs work and has more potential.

You did say ported heads and intake too. That will far more than male up for the few cubes.

I like this convo in this thread because I'm building a very similar combo. My heads are mass-produced GM CNC; not optimized, professionally ported heads. I'll likely be starting with a stock LS3 intake unless Fuzzy gets off his *** and replies to my PM. I'll be through a stick with a lightweight flywheel/relatively light clutch with 4.56 gears I understand will hurt the numbers(sure someone has a correction factor though). I do have the advantage of the solid roller, roller rockers(maybe; IDK about the GTO), fresh rings(doing this myself so this could be + OR -), Ti intake and sodium exhaust valves. Need to cc the heads shortly and decide mill/head gasket/etc. so unsure of comparison there.

jmilz28

iTrader: (13)

Don't read this...
https://ls1tech.com/forums/dynamomet...t-6-0l-g8.html

Mercier

iTrader: (15)

That sure is a LONG was from 550. But consider that the L76 cam, to me, was pretty obviously GM sabotage to the 6.0 so it wouldn't embarass the 6.2s by being only a few HP off in stock trim. Even if not going donkey-dick, there is no good reason to invest $2K-$3K in mods(just parts cost) and tuning and not slap some sort of cam in. I am sure that Pat did this to represent the bolt-on crowd since some folks don't want to dive that deep into their engine, but that thread is representing folks that are crippling their potential to avoid getting their hands dirty or voiding their warranty. Not as pronounced an issue with the LS3 with its better cam but same concept.

jmilz28

iTrader: (13)

My purpose in putting that link in here was not to point to max effort LS3 topend builds but to make you consider a FAST 102...

Mercier

iTrader: (15)

Ah. You are a dirty plastic salesman.

The FAST is overpriced. My plan is to avoid spending that cash as long as I can. I want to treat the dyno number as just that and hopefully keep myself from chasing those last few HP until I acquire/confirm traction to use said power. But I may decide to chase a number at some point. Putting on a two-piece front cover JUST in case.

Naf

iTrader: (1)

https://ls1tech.com/forums/generatio...76-intake.html

Enjoy the links and read

Mercier

iTrader: (15)

That's some good stuff. I actually read those exact threads last night when I couldn't sleep and was searching around for "L76 dyno" and similar.

That's not 550 but still impressive. I bet that a little of the additional power is in the short drivetrain and light rear/axles/wheels/tires/brake components on the FD.. Not a LOT but a few % is a few %.

Also a testament to the potential of the LS3/L76 intake. There's always better but I'm used to getting 3%-5% power gain for $1000+ part. IDK if the FAST will do that.

I am going to try to shut up now and not predict anything for mine to avoid future embarrassment..but these numbers all look good for my pending combo.

jmilz28

iTrader: (13)

The interesting thing about the FAST 102 is on a bolt on engine, it added 1% on the peaks but as much as 5% other places. It would be more on a built motor, more still with a ported FAST. Check out some of the Mamo-fied FAST intakes on LS3 motors, it's not cheap, but it is compelling. That MSD intake would be the one to go with if you're chasing a peak number, FAST for a street engine. Tony Mamo's words, not mine: https://ls1tech.com/forums/dynamomet...parison-6.html

The LS3 isn't as bad (relatively) as the LS1, LS2, and LS7 but the intake route is an easy upgrade with no real downside but the cost. I'm CONSIDERING doing headers, heads, and intake all at once until I am ready to step up to the big time again later on. I really like my factory reliability, keeps me in the car by not attracting unwanted financial attention from the SO.