So I just got a vortech low boost kit installed, haven't gotten dyno yet... Only other mod is test pipe.

Would upgrading to an after market exhaust make a big difference or minor? I read somewhere the test pipe itself is what gets the big gains not so much the exhaust.

I had an invidia on but it was too f@#king loud! Lol.

 

Minor diff. Unless you go high boost stock exhaust is fine with a test pipe.

 

Stock exhaust can flow over 400 rather well

 

That is wonderful news! I really prefer the sound of the motor than the blistering loud exhaust.