I recently (2 weeks) got a gruman step van with a 6.2 (88-J Code) The milage is around 130K and it runs real good EXCEPT has very poor low end torque. On slight grades it barely moves from a stop and generally crawls from 0 to 10mph but then seems decent as the rpm's come up. I do get black smoke under high load conditions and replaced the fuel and air filter which helped slightly. I am thinking its pump and injector time due to the mileage and they are slightly weak.
Any suggestions? Also the injector lines are quite rusty (not leaking) and I am afraid some will break when I try to remove the injectors. Does anyone have a set of pretty good lines available or a source to get them?