Increase your Ram's Payload by 50%

I think I need to get some of that canadian diesel down here in Texas...

I traded in my 2003 3/4 Cummins for a 2012 3/4 cummins. I am pretty unhappy with the mileage drop going from the 5.9 to the 6.7 engine. I was getting an honest 19-20 mpg combined city and highway on my 5.9. I am now lucky to get 15 mpg (averaged 13.5 my last tank). It will pull anything but I can't do a round trip run from Austin to Denton without having to stop and filling up (~500 miles round trip).

As for putting in heavier springs in a 1/2 ton truck... You can do it if you want. I did it on my old 1977 powerwagon. The problem is the 1/2 ton truck doesn't have anywhere near the same braking capacity. Also, the axles are much heavier in the 3/4 and 1 ton trucks. If you are pulling occasionally it should not affect the durability but over time, if you do a lot of pulling your reliability may vary.