Injectors screw in the heads, IP lines screw onto injectors, so yeah, removing the IP with the lines would probably make your work a whole lot easier. remember to only remove the IP and its lines, but leave the IP gear housing in place, else you'll be having a hard time lining everything back up. About bench-testing - nope, not really, unless you have a diesel shop with a test machine for DB2 pumps. Mel once posted a pic of one such beast, and it looked pretty scary. You can however take the IP to your local diesel shop and have them test it and re-calibrate it as needed... Or you can possibly ship the I to Mel so he can have his IP guy go over it?