Thanks for the compliments. Remember the actual header you see was already built, I did the piping that connects it to the turbo, right after the two small flex pipes.
The down-pipe is 2.5", as is the up-pipe going into the turbo. That is the biggest I could use and still fit the flanges correctly.

warmonger

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black