Looks like a solid build. A few thoughts, based on taking a '71 88" across Africa:
The 88 is really small for extended overland. Besides the obvious lack of space, the short wheelbase can be rather unpleasant on rough roads.
Unless the bottom of your fuel tanks are 10mm / 3/8" thick, you may have some fouling issues. The rear one at least, I'd taper the back to meet the underside of the crossmember. But all three are going to get hit. I just had one 10-gallon tank with a steel skid plate under it.
Plan your pack REALLY carefully. You run out of space fast and you need everything secured. I packed and re-packed several times before it was right.
Get a set of 109 1-ton springs. I was the only one who did this on our expedition (based on advice from an outfitter in the U.K.) and I'm the only one who didn't have spring issues on the trip. 109 station wagon springs on the 88 didn't cut it (two trucks ran these)
Make your own roof rack. I assume you'll run a roof top tent, which is great, but it eats up a lot of space. I extended my roof rack over the windshield a bit, supported to the windshield hinge on the tent side only. This also provided a sun visor over the windshield.
Tons more I'm forgetting (I did that trip in 2001) but feel free to reach out if you have questions.
PS I prefer "air portable" to "lightweight" since they are actually a bit heavier...