my opinion on preload is it really isn't needed unless you are using a old school engine suport bar . if you think of what is happening is that the frame horns get flexed one way during acceleration,then snap back due to the tension/load that was placed on them.this starts a oscillation effect .so all that is needed is a way too stop this action ,the new breed of frame horn to shock mount bars is a good example,air speed sels them.if there is still wheel hop there is many areas that can add to it,weak torsion bars/soft rubber torsion retainers,bad shocks,radia tires etc.
that is another thought is to try a damper on the frame horns.hmmm now i'm thinking of something.