I have a 1997 dodge ram 1500 sport 4x4. I've been had this truck for years and just recently rebuilt engine which is a 318. I have a manual transmission and a 6 inch lift on the truck. I am lacking power in the truck. It was the same way before I rebuilt engine. When I'm in 5th gear I can put the pedal on the floor and it just does nothing. No power at all. Factory rear end. Any suggestions?