I would be careful with the IPD header, I bought one about a year ago and after a front end alignment, the unit would hit the top of the A-arm at the back bushing. Grassroots Motorsports had the same trouble on their 122 when they had it set for 2 degrees negative camber. Unlike them though, I can't afford to replace it with one of John Parkers 4-2-1 units, so ground down where it was hitting on the A-arm and shimmed up the engine with washers at the engine mounts. It is satisfactory now. Although one disadvantage to shimming the engine up is that it reduced the space between the bellhousing and trans tunnel, making it hard to get to the nut on the upper starter bolt when had to replace the starter a couple weeks ago.

See the last paragraph of the update for August 21st for their comment on the header at http://grmotorsports.com/volvo122s.html

Best of luck,
Brad M. 1970 144s