Chevy express 1500 vs 2500 vs 3500?

I would really appreciate it if someone could explain to me the main differences between chevy express 1500/2500/3500, i'm currently looking at chevys but feel free to give me examples from what you know, ford, dodge… Etc. So i know the numbers stand for hauling capabilities, 1/2 ton, 3/4th… Etc but not sure if they all come with the same body size and cargo space, so is the 1500 and 2500 have the same cargo space? I'm looking at years around 2005, i also know they used to make them as v6's also, would that be a good idea? I'm looking to convert the van into a camper for cross country touring, gas milage is important but don't want to sacrifice too much on space and possibly performance specially since i will be spending a good time and money building the thing up from scratch, plus i'm considering resell value, the truck would most likely not be used for hauling or excessive weights, maybe a dirt bike + everything that will be built inside, bed, cabinets… Etc, would i be sacraficing on performance going with a v6? By the way is there any reason i should reconsider going with a chevy? Is there a reason you prefer ford? Thanks for reading, looking forward to your responses.

I think you have to go to the 2500 or 3500 to get the extended version. A 3500 is going to have the 6.0 engine unless its a diesel and be set up for heavy towing / hauling so its not going to be good for economy. A 2500 could go either way for the gearing, it could be more for hauling or cruising. I think you can get the 5.3 and the V6 in the 2500 but I would not expect it the economy to be a ton better, you are still having to roll and push a huge brick down the road and through the air. A V6 is going to be working its but off so don't expect any savings there. The 3500 is going to have big brakes which are more expensive to replace and weigh a lot more but should last a long time if you are not working them hard.