Thanks for the replies.
Yes I hope to get more replies on this tread, since I want to start building that exhaust by Tuesday as soon as my new turbo arrives.
I was in George yesterday and popped in at the local Powerflow shop. They wanted to nail me R5500 for a mild steel pipe.
I have a business card in my desk drawer of a place in Bloemfontein that quoted me R2200 for a Stainless steel pipe. (This price did not include fitting)
Since I stay in Graaff-Reinet and we are very limited to what is availible, I decided to buy lengths of 3" pipe and also got a piece what has lots of various bends in it, so I will cut and weld in my workshop.
I also think that since it is diesel, a mild steel system should be fine.
Michael Thanks for your input. I value all your comments and prompt reply. I would like to have more comments on this tread. Otherwise I will go completely free flow and if I find it to be noisy, I will install a free flow box next month. Doing a turbo and exhaust in one month drained my resources a bit.