Y does slp not use Bilsteins that are properly valved for an fbody's ride height? Is it to make it ride alittle softer and nicer?
Is it so they can effectively use a 21mm sway bar in the rear?

 

The spring, not the ride height, Bilstein HDs are valved for stock springs and the SLP Bilsteins are valved for thier 300-450# front .75" lowering springs.

 

will the HD's be a good match for the 1LE springs? what are the spring rates of those? anyone?

 

360# fronts, 130-180# rears(?)

www.1le.net
http://www.socal-fbodies.org/resrc.html

 

the HDs actually have less dampening than the SLP units. I believe this is because the HDs would ride to "harsh" for a stock car.

 

Actually SLP Bilsteins have much less rebound damping but a little more compression damping than HD's. HD's stock do not have enough rebound dampening for stock 290ish front springs from my own experience. How SLP uses their settings for 300-450 lb/in springs is beyond me. Skip the SLP's and get a set of Bilstein HD's and have them re-valved by Strano for your specific use/style/setup. This is what I'm doing my Bilsteins are in CA as we speak.

 

Bilstein B46-1913 front -Bump 159 Rebound 279
Bilstein/SLP B46-2071 front -Bump 130 Rebound 397

 

Opps got it backwards I should've double checked. Sorry.