I am wanting to know, if I install a new cam and heads on my stock lt1 what is the duration and what heads should I or can I go with and still keep the car emissions legal, can anyone give me any info on this?

 

What are your goals for the car? Also how many miles are on the engine/trans? What year car? Manual or automatic trans?

 

Go here and read, it will assist you
http://elliottsportworks.com/

 

Couldn't agree more. The guy knows LT1 stuff inside and out. I've always enjoyed my interactions with Lloyd Elliott, he's a good egg

That being said we really need more information on the car, preferably with enough grammar for us to understand.

 

94 z28 164000 miles automatic trans, keep it a daily with a little more horsepower is my goal. Maybe 425-450hp. But still emissions legal.

 

That's higher miles to be adding more HP to. You should at least consider a fresh rebuild with new rings and bearings if it's your daily driver. Either way some mild heads and a XE503 [224/230 @.050] is a good all around cam size. I daily drove one of those and it did well. That would put you around 425hp at the crank. However you didn't mention if you've done any supporting modifications yet. Headers, Cold air, catback, etc

 

I have been wanting to do a stroker block, but then I had the idea of "why not just do a stock lt1 bottom end with better rods, bearings and pistons." But with a stock fresh turned crank" that now has become a thought. Just adding better heads and cam. I was thinking maybe a lt4 hot cam, afr or trick flow heads. As far as I know the car is mostly stock ( I bought it the way it sits). It has k&n mass air and flow master exhausts and as far as I know that's the only aftermarket parts on it.

 

Don't forget something other than the stock exhaust manifolds too. You may also need bigger injectors.

 

Have the crank inspected, and bearings replaced as required. The stock crank and stock connecting rods are more than adequate for a non-poweer adder setup. You may find you need the block bored, just to get the bores round again. That would require new pistons.

As far as the heads, unless you want to go over 500HP at the flywheel (and you won't be close with the LT4 HOT cam), you do not need AFR or Trick Flow heads. Ported STOCK LT1 heads can support up to 500HP. Costs way less.

Do as suggested above - look at what you can do on a site like Lloyd Elliott's. Get something a bit better than the LT4 HOT cam. A good head proter can give you excellent guidance on the matching cam, based on how you want to use the car. A thumper for the track might be great for peak HP at very high RPM, but isn't going to be very friendly on the street.

Bersaglieri gave you great advice.

 

Sound advice from Injuneer.

Don't let a shop talk you into paying big money for aftermarket rods and crank. Recondition the factory ones if they are in spec, maybe add ARP bolts to the rods for security. Ported stock heads will leave you with some budget to get the bottom end worked over and a decent camshaft. Look at Lloyd's LE1 heads and an emissions cam. That'll be a potent combo but keep you emissions legal. AS&M or RK sport headers are a good way to open up the exhaust but keep you emissions legal as well. Cruise the classifieds to find some items used, that leaves more money for good rockers, injectors, and stuff like that so you don't have to buy crappy parts to finish a project.

 

Thanks for the advice and the link it will be a big help!

 

Great advice above. Headers, 160 thermostat and a tune really woke my car up. I dont have emissions in my county thats why I ran a 3" ORP (Off Road Pipe) in place of the catalytic converter. I am probably going to go with Loyd Elliot Port Works for my heads and go with a CC503 cam in the near future. Good Luck with your build.