Thanks Dino. You know, I was in a bit of a rush when I replied the first time but Ive been thinking a little more about it. You're asking about a set of 6" x 52" springs in the front right?
We are only talking front spring swap here.
My front springs are (somewhat) stock 1/2 ton rear springs. They are a combination of the '74 main spring with the eyes and a few of the original 1963 K15 leafs peppered in for ride quality and BC I had broken a couple of the others.
Currently, my truck currently sits 1/2" to 3/4" higher than it did when it was stock (pre spring shackle swap). The "kit" I used came with 6" shackles for the rear of the front leafs. The front spring mount is in exactly the same location as before.
Its pretty widely known that the '60-'66 K trucks sat a little higher from the factory.
IMO, the front swap doesn't give a lot of lift in and of itself with stock springs. Lets say an inch or so just for S&G.
I would think that if you used a 6" spring lift on the front of the Burb, you might end up at 6+ (maybe 7") when all is said and done.
There may be a benefit hidden in this though. IIRC, most lift springs tend to be a little shorter from eye to eye than their stock counterparts. If you are running something similar to the B52s, you will have the ability to locate your axle a little better and also tailor shackle angle to suit your need / wants.
I keep imagining 6 more inches of lift on my truck... maybe if i was 20 years younger.