Durastar 4300 with Cummins ISB

Anyone running a newer Durastar 4300 with Cummins Isb 6.7l ?
Ho do you like it? what kind of fuel economy are you getting compared to your last truck?
I have a 2007 4300 with a Dt466 240Hp getting 7.3 mpg, either looking at a new truck or overhauling existing DT466 in the next year.
Im trying to find stats comparing fuel economy of 2007 DT466 to newer durastar with Cummins Isb

Any information would be appreciated
Thanks Leroy

 

Thanks Bakerman
My current truck has 355,000 miles and is ten years old, I plan on reitiring in 6 to 8 years, I realize I can rebuild the DT466, but dont know if I want the last years before retirement to be running a 15 year old class 7 truck with half million miles, as I had a few electrical issues in the past couple of years. Cab is starting to get some rust!
That is why I am debating a new truck or the rebuild, If I go new and can gain 1 or 2 mpg saving myself $1100 plus a year on fuel at the current price of $2.00per gallon.
The sales people all claim better fuel economy with the new ISB 6,7l, but very difficult to get some good testimonials!!


LEROY