my truck didnt do anything special but i figured id post about my cousins truck. late 99 with a dp tuner 80 econo, 3.5" dp, 4" side exit, K&N cone, powershot propane, & stock trans, 165k on her, it ran 15.5 @ 85 on fuel, 14.4 @ 93 on the propane. i was really impressed with the propane runs, 14.4 back to back twice, 1.9 60 ft times, i dunno if these trucks gain a lot of power cause of the lack of hpo psi or what but ive heard people say they didnt get crap out of it. anyways hes got a pretty quick stroke, he may sell the pane and go with nitrous soon, we'll see.