About to purchase a 93 5.9 single cab 2wd D250. Injector pump is leaking and ignition switch needs replacement. Switch is easy. How hard is it to rebuild or change seals on injector? Any techs near Garland i can trust for bigger issues? And is there any other problem areas i need to look at? First Diesel was a 6.0 and it dang near made me strangle myself. Thank you