A couple of good new ideas.....I did not think about the intake manifold/exhaust manifold or other powertrain options.... Yeah, it's all up front and perhaps costly, but some performance benefits and could be significant weight reduction. Any aluminum parts you could add would be helpful...aluminum water pump(?no idea)....lightweight fan....lighter weight exhaust(?)....maybe some others. It sure would be on a V8....does that have a V-6?
The spare wheel left behind at home is an interesting one too. I thought about mentioning it but held my tongue. I do the same. I don't even OWN a spare 19.5" wheel. The guy I bought it from drove to South America and back with no spare, just a patch kit and good compressor. Amazing. I wouldn't go THAT far, but traveling around the US, especially with a dually where I could limp with 5 good wheels/tires I just don't worry about it. That is a pretty good hunk of weight.....but.....with only 4 wheels it might be too risky for backwoods/backcountry travel. At the very least, up front, or in the rear seat area like Steve shows would be a help.
I'm also not so sure about the ratings assuming 100% usage and going over "once in a while is OK" thought. I talked with my dealer when I had to replace my entire brake system (well, at least all the wear parts plus one or two calipers) at 60-70K and said "WTH, how come I only got that many miles?" He told me that with my truck (and it may be different with "commercial" type trucks) that GMC only figures your duty cycle to be 50%. In other words, 50% of the time you will be fully loaded and 50% of the time you are closer to empty. This makes sense for work trucks and delivery truck etc.....on the way back you'll be empty, right? So at 50% duty, I might have gotten 100K+ on the stock brakes. My camper is on nearly 100% of the time, plus I am at the 100% GVW of a 5500 basically all the time (that's the number for all my components EXCEPT the rear springs.) If I had to guess, the engineer's that are concerned about shaving every last bit of dollar out of the parts used, also may figure a 50% duty cycle of 100% of GVWR. Yeah, there is some CYA and legal involved, but the engineers are pushed to make the vehicle 'cheaper' to make the most money too.