I have a 2007 Trailblazer with a 5.3 that I've been wanting to do an exhaust on. Only thing I've been able to find are for the SS (Which I know will bolt on no problem) but they're all 1-7/8" headers. Since this is a truck and my dailly, low-end torque is what I'm mostly after and I'm concerned primaries that large or going to make that suffer. So what's everyone's opinions? Thanks

 

Dynos have been showing basically no difference down low with the header differences when it comes to 1 3/4 and 7/8.

you won't notice the difference down low but gain more up top. Run it.

 

I’d run them. I feel even factory LS heads flow well enough that running 1 7/8 has been Just fine.