four years ago when i got my 81 300 cd the tranny did not shift correctly. replacing two vacuum valves and while i was at it the levers that operate them corrected the problem. you seem adament that they are usless. i am reluctant to remove them alltogether. i am going to block the EGR valve(allready done) as before i pulled the sludge catcher i tried it with no noticable change in behavior. once i get my alternator back from rebuild and all runs well i am going to try your sugestion. simpler is better after all. have you had bad experiences with the black box and how did you remove it. i have 5 lines running to it. i am going to block them all at the connector and try it unless you have a better way. thanks for all your help and humor.