Going Through CV Axles Every 6 months

I've got a 97 extra cab with a leveling kit. I bought the truck with the lift on it. The lift uses 2 5/8" spacer blocks under the leaf springs and 1 1/2" spacers on top of the coil springs. I know this is not the right way to do this, but it's the way I bought it.
Anyway, this truck has gone through 3 sets of cv axles in the last 18 months. When I say gone through I mean the boots tear and then destroy the yoke immediately. The last two sets were from Napa.
Does anyone have any idea why this is happening? I've heard that the spacers on the coil springs change the geometry of the cv axle and that's why they're wearing out so quickly.

Any help would be appreciated.

 

Truck sits too high, needs a diff drop and/or boot slide mod.

FWIW I have seen plenty of people run CVs with torn boots and they still work fine because they still hold most of the grease. However if your truck sits too high then it needs to be fixed period.