FWIW, I'd guess you have a 2-1/2" lift on there... Even the stock "HD" 3 leaf front springs had noticeably negative arch on blazers, and it appears yours are just about flat, which would be right for a 2-1/2" lift...
I believe Skyjacker had a 3-leaf front pack on an older "softride" kit. Other mfg's may have as well.
A mid-80's blazer should have four leaves in the rear pack, so you may have an add-a-leaf, if not a ~1" block and an add-a-leaf...
Nice Blazer, BTW!!!
It looks interesting with the 17" wheels...
Since you just bought 6-lug wheels, you might consider offing all the 8-lug axles and finding a Semi-floating 14 bolt 9.5" axle with the 6-lug pattern. Sure, it's a semi-float, but you'll have a much stronger axle than your current 10 bolt rear, and it'll work fine with your new wheels. If you could find one with 4.10's and a factory G80 "Gov Lok" you'd only have to change the front axle ratio to match.
Car-part.com shows several available around me with 4.10 gearing... Look for a rear axle from a '98 2500 with 6 lug hubs and 4.10 gears and see what pops up. Then peek at the truck glove box and find one that has G80 option listed.
Oh, I believe the 2wd version would be closer in width to your current Blazer front axle... The 4wd axle is just a bit wider IIRC...
Good luck!!