**Header installation ?'s**
 

So just wondering what i will need to bolt up a 4-1 header w/ 2.5 inch collector to a stock gsr cat.... or do you guys think its better to go with a high flow cat?? LMK guys thanks

yup
 

You'll need some sockets and wrenches is really about it. AIR TOOLS FTW LOL. High flow cat is always nice and may as well do it while you're down there.

x2 ftw lol, i love my big ass compressor i have at my house lol, always use those damn tools when i can

That header will not bolt up to the oem GSR cat. The flange sizes are mismatched. You'd need to hack up the oem cat and then get a reducer to taper from 2.5" - 2.0".....which is horrible from a performance standpoint.

I'd get a high flow cat + larger exhaust (at least 2.36" or 2.5"), so you have a complete system.

i also have a ITR b pipe that i want to use with this set-up.. will this bolt on to the gsr cat?

yes. Same flange pattern.

I have a high flow Carsound Cat that I'm selling for $135 (if purchased separately).