The uppies are at the rear of the engine, running from the exhaust maoifolds up to the turbo. Look for black soot marks on the firewall, and around where the pipes hook to. You can pull the intake hose off the turbo to check the vanes, and as stated the edges should be sharp and straight.
1985 F250 Reg. cab 6.9,94 factory turbo, zf5 speed, 3.55 4X4, flatbed, dual 3.5in. stacks
1990 F350 SRW Crewcab 7.3 turbo 4.10 zf 5spd 4X4
1997 F350 SRW Reg cab powerstroke 4.10, zf5spd 4X4, 3inch downpipe, 6637 mod, intercooler
1996 F350 Crewcab dually 4.10, E4OD, 3" downpipe, 6637 filter
1996 F350 C&C Dually reg cab 4X4 flatbed Zf5 4.10, 3" downpipe, 6637 filter