Flex pipe might not mimic the real stuff enough to be a good pattern. At least the stainless steel flex pipe I used wouldn't. I did use an 18" section to separate the front portion of the exhaust that hangs from the engine and transmission from the last of it that hangs from the frame, I only asked it to make about a 3 degree bend although it will do more. It is "flex" pipe, but nothing like the 4" or 6" centerline radius bends I used for the rest of the 4" exhaust.
I suppose you could use some PVC bends to get an idea of the different bend angles available, but if they aren't the same centerline bend radius as what you eventually use it may just frustrate your mock-up to real life transition.
If you make it from pre made bends just buy a bunch and return the rest. If you have very little room there is no substitute for the real thing.
Grigg
