The hydraulic lifters are making noise? Someone on her might have the info on switching them out with manual lifters. With the dsm drivetrain, we swap them out to the 3G lifters or 3rd revision lifters. The opening on top of the lifter is larger for more oil to pass through and eliminates it. I am not sure if the revised lifters for the dsm 4g63 is compatible so might have to find the info on the solid lifters from older trucks.