i have 4" lift tuff country coils on my 78 bronco, love them. they are firm, little bumpy ride on the road, but i think it rides better that way than the soft flexy coils you can get. also, on the dunes they are awsome.
my 79 has a super lift kit on it. The rear has 2 inch blocks and an add a leaf, and the front has new springs. The guy I got the truck from claimed it's a 6 inch kit, but it may only be a 4 inch lift. From the front bump stop to the top of the axle it's exactly 6 inches. To the top of the icc lights it's 7 foot tall exactly, with 33 inch tall tires on it. I only took a short trip on the highway with it so far. Rode really good, not a lot of extra sway or harsh ride. I'll be ripping the lift off and putting a 9 inch lift on it in the near future. So if you want a used kit, maybe we can work out a deal.
just be careful running EB springs on fullsize trucks, will wear them out much faster, the old fullsizes are a lot heavier than the EB's. the Tuff country's will be straight rate, if you want the top of the line coils then go to Cage Off Road, they have awsome flexy coils for our old fords, and they make some awsome extended radius arms that add a ton of flex.