Ben,
The headers look nice. I do not want to make you ill but I just found a toy you might like. Google Sketchup is a free 3D cad deal from the search engine folks Google, just download it. There is an add on from a Dutch company, trial version is a bit of a pain but no serious problems, this add on does pipes, yes any kind of pipes. The company is 3SKEng.
Check it out, for my 914 / 6. All tubes within 1/2 inch on second round. The colors I added and denotes what angle the bend is, 15,30,45, 60 and 90.
Beats cutting and tacking.
PFM