Lowering a C20-CS Longbed

[HYPR]

Ok, I know most want to lift these 3/4 tons but that's just not me.
Looking at two vendors for Drop spindles
Performanceonline DS7187 2.5" $449.99
Gmcpauls 19722647 (Fits 71-72 C20-BO until May) 2.5” $410.00
Both claim to be American made.

Now comes the rear leaf springs which are spring over axle so using lowering blocks is out. Since I will not be towing my thoughts are to remove the two helper springs which gives me about 1". I can dial in some dampening using a set of QA1 double adjustable shocks for ride. So far all the 2.5" Lowering shackles are either made for C10s '73 or newer and POL makes the RHK7391 which offers a 3-4" drop but only made for the 73-91 C30 which according to my research is the same width spring so I am not sure why this wouldn't fit and just toss the mounting bracket. I can't seem to find anything for the '72 C20 (2.5" wide leaf spring) so I am looking for recommendations before I resort to having my son fabricate some (Fabricator) by welding up a set. I really don't wan't to go through the expense and experimentation of de-arching the springs. So any assistance would be appreciated.
Bob