Flip kit drop. would it be 5" or 6.5"

[74Pumpkin]

I am going to put in a flip kit on the 74 stepper. It has the heavy duty spring. currently the distance betweeen the top of the spring and the bottom of the axle is 6 1/2 inches. It has 8 leafs in the spring.
If I put in a flip kit would this drop the rear 6 1/2 inches? Or am I missing something. Also. Do I have to worry about the angle of the driveshaft into the tranny?
I plan on putting in 3" spindles. I might have to also put in 1-1 1/2 drop springs also if the rear drops that much.