Hey guys.

Im a little outta place but hey,, Its a GM motor so here we go.

My current exhaust system consists of Hedman Headers #68600
Dual 2 " tubing leading back to Blue Streak Glass packs then Dual 2" tubing out to the tail.

I don't have any cats in the system.

When I first start the motor and untill it warms up it sounds strong.

But.. After I drive somewhere and come to an idle there is the normal low rumble but also a funny puffy sound coming from both exhaust sides. The engine is still strong and idle is smooth. Its just at the rear that you hear the sound of AIR. Its really hard to describe the sound to you. Its just not right. I am wondering if this may be due to the cheap glass packs and no backpressure in the system? I don't know much about exhaust or glass packs but I did look at the glass packs before they were installed. You can look directly through the middle of them. Aside from the vents or whatever you call them that are around the outside edge of the tunnel.

The exhaust only sounds like this after driving. If I let it sit and idle after FIRST starting it for the day it does not do it. EVEN after it comes down to normal RPM and warmed up.

I do not have a balance tube between the two pipes. I have been told that this may be a good Idea and my also take care of the problem.

What would you recommend I do. Would I get better performance putting in a muffler system rather than the free flowing glasspacks? Should I put in the balance tube first?

I am running an all stock 5.7 TBI with no mods other than the exhaust I have just described. Do you think I may need to have a custom chip made to help the computer understand the free flowing exhaust or should I put on some mufflers to build a little back pressure.

Thanks guys, this board rocks. SO MUCH INFORMATION