coil spring specs?

[MarkoWyo]

Does anyone know a source for original coil spring specifications for Suburbans (mine's a '71, 2WD, C10). I'm looking for the engineering specs like rate, load, & dimensions, not just "heavy duty" or "sweet ride" or "3 drop". Those specs are not in my shop manual, but I bet are out there in some GM/Chevy book, .., I haven't been able to find them on the web.

Moog/Federal Mogul have a great selection of springs, with full specs, should allow me to fine tune my ride nicely. But first I need to know what I currently have installed. Yes, I could just take the springs out and spec them out on the bench, but that will not be a convenient approach for my situation.

Thanks in advance. MarkoWyo