Hi mate,

I just fitted a Redback Exhaust to my 4.2, engine was stock with factory exhaust. System I bought came with dump pipe, straight through with no muffler.
I fitted it myself, everything lined up good and seems to be excellent quality. I haven't had it Dyno tuned yet, but the difference is already impressive, ute is quicker and sounds awesome. The turbo seems to wind up quicker.

Today I did the EGR block and removed the butterfly from the intercooler, didn't notice any difference in power, but getting it tuned soon to hopefully see better results.