How much rear suspension travel?

My '72 Swinger with relocated springs and an 8-3/4 is sitting too low in the rear (fender lips are only about a finger-width above the rim).

I put on Calvert (Rancho 9000) shocks which have just under 8" of travel. (They are 14-1/4" compressed, 22-1/8" extended). They're mounted in the stock location which I estimate is at a 30 degree angle - so that means the rear axle deflection cannot be more than 6-3/4" total. Does this sound right? I thought it could move up and down more than that...

Anyway there are only about 1-1/2" of compression currently available at rest so I know the springs are way too flat. New springs on order. Meanwhile, should I expect the shocks to sit in the middle of their operating range (4" shock travel in either direction)?