Sounds like it is free decision, not forced by lack of 8 grands for diesel?
So why don't you do your homework the right way, grab pencil and paper and do some calculation.
How long you plan to keep the truck, or what more important how many miles do you plan to run before disposing of it?
Diesel lately can be bought cheaper than regural and last month I was filling up for $2.19-2.39, while my dually with my monster 6000 + lb camper averaged 12.5 mpg with CC at 60 mph.
So adjusting the numbers to your set and your driving style - calculate how much fuel will cost you in predicted truck life.
Now do the same for gasoline option.
With fuel prices fluctuating a lot in last years, I still was coming even with diesel option after driving +- 50k miles and then was cashing the savings.
Not even counting resale value and the time spend at gas stations when you have to fill up more often.
The smile 440hp (who you don't even hear) gives you >>> PRICELESS