I have an 04 6M GTO with L/T, catted X and an MS3 cam. I was pulled over and the cop spotted the L/T. Now I am thinking of playing by Cali's rules and getting a stock manifold with stock cats. I am guessing this set-up along with the MS3 cam will make the car a dog down low. I am thinking of a 224/228 .534/.537 or .581/.588 The car is my D/D and has the stock gears. Any other suggestions?

 

I'm not too familiar with emission laws in California but I thought as long as you had cats, you can do whatever. Check with your state laws and see if it's possible to run high flow cats. Be warned, they tend to be expensive. Or, you can purchase "dummy" cats. They are cat housings that are hollow that you run your pipe through to give the appearance that your car is equipped with cats. Again, I'm not sure if California performs a smog test where this will not work.

 

Hi-flows are illegal here. Just about any cats besides stock is illegal. The cop gave me a REF ticket. I will have to smog it a ref station and they check all emission equipment with a fine-tooth comb.

 

LTs are illegal by federal standards. Doesn't matter what your state says. I would look at Thunder's cam designed for stock manifolds. Old Man cam is the name I believe.

 

If you want a cam that will also pass the sniffer, you'll need to go smaller, what you want is a cam with at least -4* of overlap. With the stock exhaust manifolds you'll also want at least 6* more exhaust than intake duration. A 219/227 114lsa w/LSL lobes has -5* overlap and should pass with a good tune.If you still want a larger cam then the lsa will have to go up. A 223/231 116lsa would still have -5* overlap so your still good. If the sniffer test isn't a major concern then a 223/231 111lsa w/lsl lobes or a EPS 224/230 111lsa would work great.
http://www.engpwrsys.com/index.php?a...od&productId=6

 

pretty brave guy . all the things i have heard about how bad cali is and you just said screw it lol,sucks its like that , i would think procharger , if its your dd , i think procharger setups are all good, i say that because doesnt seem like you can do much with the motor, small blower cam, some kind of fi,those guys out there really need to get a grip, i have driven my ms4 tsp dual car all year and not had one issue,

 

Cali rules do put a damper on things. My car did "pass" smog out here with the L/T and MS3 but since the popo pulled me over, it's a different story. Prochager is another option, just have to save the coin.

 

408MARO just had a build thread on Cali-crap laws...he switched to 243 heads
and ordered an EPS 222/230 cam to work w/manifolds...I believe he ended up
around 370 rwhp and was happy with the drivability

 

yeah I'm from Cali too and I can't believe how strict they are. IMO, if it passes tail pipe, it passes tail pipe. Heck, I've heard of people that could get cleaner emissions from a bigger motor. i.e. later model engine, but no that has to be ref'd too. For instance the stock 2.4 in a fiero vs. a modern LS motor.

Anyhow, thats why I'm going with a pre-smog car. Putting an LS motor in my Corvair. Besides in 10 years it will still be a classic of sorts and in 10 years most newer cars are just worn out or old news.

For the OP, I would keep a stock motor and just do a swap every two years. Buy some CARB headers to make the cops happy, which should've been a no brainer from the start. Cams and retune you could get away with if you can find a smog shop that will test run off the record to make sure you're in spec. Get rid of the carbon fiber hood, it just screams 'racer'.