Those are 26" wheels? they look like they belong on the truck ( like the stock 22's) I'd like to see these side by side. definitely lower that . you might only be able to do a 2 / 4 drop without rubbing issues. also depends on the roads in your area and how often you drive.
and welcome to NHTOC
stock rims and 275 45 20 weigh closer to 81-83 lbs. my 22 reps with 285 35 22 Hankooks weighed in at 81 lbs. freakin heavy! I am going to weigh the 275 45 22 Pirelli with the stock 06 HD rim when it arrives to compare.
your 26 set up prolly weighs in at 70 -75 lbs. that's not a bad thing. if you get a chance weigh them on a scale to get the real #'s
OK Kumho Ecsta STXKL12 305 30 26 at tireseasy ($585 each)
and those weigh in at a whopping 49lbs!!! ( i got this info from Kumho tires site)
And to add to the mix, the stock Harley 22 Pirelli tires weigh 40 lbs each at 31.8" tall. quite tall & hefty!
where as a Yokohama Parada spec 265/40 22 is 30.5 tall ( about what I'm looking for) and weighs 36 lbs. much better. and will work with the GF drop (less rubbing action). just gotta make sure about wheel well gap.