I hope this question does not sound confusing but here goes. Just got a 87 GTA w/ a blown up 305TPI. I also got in the deal a 350TPI from a 88 Formula that I will switch the blown out engine with. While the engine is out I want to allow it to breath a little easier and run w/ less load. So I want to put on an overdrive pulley, electric water pump, and I am looking at buying a set of used headers.

Now this is where i really need your help. The headers are from a 88 GTA L98. The headers come with the Y pipe and do have an O2 hookup. They do not have the smog tubes. What does this mean? The headers are 1 1/2" in and 3" out. I want to keep all the emmisions stuff legal so what problems would I run into here?

I was introduced to this site recently and have found it is fruitless to chase hp/tq w/the L98 since they reach there ceiling early. So until I can decide what I want to install for big hp/tq I want to let the engine breath easy and get good gas mileage.

With this situation what do you suggest. I realize I need to do something w/ the rest of the exaust system becasue its a stock 305TPI setup right now. I hate loud obnoxiuos sounds but do like a nice low rumble. Is there any hope for me with these circumstances. Past these things I really dont want to do any other mods becasue it seems not to really yield much with the TPI engine.

 

Smog tubes (also known as AIR tubes) are steel tubing that screws into the heads/manifolds at each exhaust port, they hook up to the Smog pump and AIR diverter valve system that is part of the emissions controls. The purpose of the system is to feed extra oxygen into the exhaust to enhance the catalytic reaction in the catalytic converter and burn more exhaust gasses.

If your state does not have a visual inspection of smog equipment, you can run without the system. However if you have to go through a tough inspection like NJ or CA, you will need to have a functioning pump, diverter and plumbing hooked up.

There is a long running debate about whether the smog pump system is necessary or just useless crap. There is a sticky at the top of the forum about it also will give you more info than you'll ever want to know.

headers, ypipe, no cat/hi flow cat, full cat back, will wake up the TPI whether it is a 305 or a 350.

TPI can make respectable numbers, especially solid low end torque. By chasing HP what kind of numbers are you after? What is your budget? Then decide on a good platform to start.