what would be a quallity brand for a header to be put into a gs300?

 

the IS300 header will work on the GS300 also. If you have a 2001 and up the y pipe will also fit. If you the the 98 to 00 it's a little short and you will either have to mod it or use your stock one. OBX, Alpha Werks, Turbo East, Toyomoto and HP Racing all make them for the IS300. Hope that helps.

 

here are their websites. also obx, alpha werks and turbo east supposely use the same header design. toyomoto and hp racing supposely use the same header design.

http://www.obxracingsports.com/

http://alphawerks.com/

http://turboeast.com/

http://toyomoto.com/

http://hpracing.com/

 

i would think there'd be different diameter header for NA or FI, no??

how much gain does a GS300 get from aftermarket headers and Y pipe?

 

Should get around 12 rwhp...maybe...a little more with some tuning