Just a few questions...
 

I have a 2008 Chevy 1500, it's almost paid for so I don't really want to trade it in or sell it to upgrade. It has the 5.3 in it now with 10k and it's starting to use some oil, do instead of rebuildin it I thought about swapping in the Dmax. I know I'll have to upgrade the suspension, get an Allison etc etc but I was wondering as far as the actual frame goes if there's any differences between the 1500 & 2500?
I'll do some more searching to find out what all the swap Intel but it can be that difficult. I'm pretty savy when it comes to mechanics.

Id say get another 5.3 and turbo it with a cheap turbo, 80lb injectors and tuning, and good flowing truck heads they can make beast power, just got to put a 4l80E behind it instead of the 60E

check out sloppy mechanics on youtube, or google it for his website that documents how to mod the 5.3 to see what I mean

way easier and cheaper swap and you can have a lot of power really easy, north of 600hp without breaking a sweat, the 5.3 is the same basic block as the 4.8, 6.0, ls1, ls6, ls7 etc.

edit: here check out this video