[Gav]

I had toyed with the idea of stainless but could not be bothered with the welding. The pipes you are welding together require to be filled tig gas whilst welding in order to get a reasonable joint with no leaks or porosity.
To be honest I just can't be fagged and the coatings available for pipes now are great.
All up I have bought 20 small radius bends, 4 large bends, two flange plates for the heads, 2 colectors, 4 reducers, 2 3" bends for the tips, 2 3m lengths of 1 3/4" pipe and 1 3m length of 4" pipe.
All up it has set me back around $800 bucks.
The four larger radius bends are the killer as I was charged for a die change for their bender.
I was going to tig every join but will probably just use the mig in the engine bay and linish the welds.

Gav