I have swapped an 01 ls1 motor onto my 98 firebird formula. Before my motor install, I decided to put a camshaft, Texas speed ms3. My car is running but feel no power as in like if it was asking for air. I did install everything I needed for that lift. Such as springs, rods, timing chain, oil pump, etc..
I have the stock heads for the 2001 ls1, and I have my stock intake manifold from my 98 ls1 motor. I took my car to get tuned but my car is still running very wierd. My question is this.
''do I need to get a bigger intake manifold\throttle body, or is there just something else making my car run like crap?"

I did get the 48lb injectors.

 

That intake will be holding you back quite a bit but it should at least run okay once it's tuned. Are you saying it's running weird after the tune?

 

I'm willing to bet the tune is not properly configured for those big injectors.
I would not use such a huge injector unless planning to dry spray the engine.
The MS3 is a "no Joke" type camshaft and in a stock LS1 needs plenty of crutches to do it's thing. Most cam only guys run awesome exhaust systems...not just 150 dollar E Bay stuff: and also FAST intake manifolds with big throttle bodies. 4400 stall and at least 4.56 gears will also help.
thicker 11/32 push rods as well as trunion upgraded rockers to help support the 7200-7400 rpms that camshaft likes.
In this particular example IIWM I'd find a LS6 intake with the factory 28.8 injectors and have it tuned at a different shop. I would also start saving for a pair of Trick Flow 205 heads to eventually boost the compression ratio to around 11.75 which again that cam will love.

 

If any help with my information, the pcv line is disconnected. Why? Because if I plug it in, my car will stall. It's a manual car also.

 

It's been running like crap before and after the tune.

 

Id run stock injectors with that setup.

 

So the car was tuned with a big vacuum leak? Key words being the last 2.

So what does the PCV consist of right now? What goes where?

Also, I'd still think 28.8's will be maxed with that setup. Start looking for 36's.

 

Yes it was tried to be tuned with that pcv disconnected. When I connected it, it would stall. Say u barely tap the throttle, it will turn off. I have no idea why. My guess was that I needed a bigger throttle body/intake. 102mm I was thinking about.
Like if it was asking for more air.