Find someone who has enough experience and knowledge to check something called "Ackerman". Basically, it's the imaginary point around which the vehicle pivots while in a turn. With the wheels turned to the point where you normally experience the squeal, a line drawn through the center of the rear axles and one drawn at right angles to both front wheels as they're turned should intersect at a point several feet away from the vehicle. If they don't, the angle of the offending wheel needs to be corrected by bending the steering arm. Another term for Ackerman is "toe-out in turns". If there's a good quality round track racing shop in your area, that's where I'd begin looking for somebody who really understands steering geometry.
With the amount of steering and suspension butchery you've described, I'm not surprised you're having trouble. Very few people who set out to "improve" a vehicle's ride height and/or handling know anything at all about how to go about it. Just because somebody is willing to solve all your problems by selling you something doesn't mean they actually know what they're doing, or care at all if it works once they get your money in their pocket. Buyer beware!
Jerry
