6.5 td instead of 454tbi

[Rot Box]

I average mid 20's mpg with an occasional 27 mpg on highway using highway tires and lower 20's when aggressive tires are used.

Good to see someone else getting good mileage out of a 6.5. I sold it a few years ago, but while my pickup (K2500 4.10 gears, 4L80E) was lighter than a Suburban I would count on 22mpg unloaded with a all-time high of 27. Imo the DS-4 is a great pump it and the GM-4/GM-8 turbos complement that motor VERY well.