Merry Christmas
Using the lowest hole will not have anything to do with messing up the pinion angle up unless when you are in it you are unable to re set your pinion angle back to the angle you run, be it 3 or 3.5 degrees. Some cars are not built properly with housing bracket location in mind and have a limited number of holes that they can use and still be within the range of adjustment of the ladder bar upper and lower adjustments for seting pinion angle. You do not know if this applies to you unless you change the front mount position and readjust your pinion angle. The answer to your wheel standing issue still lies in the height of your front mount and the rate of pitch rotation set in your front shocks, like Johnny mentioned by limiting front end travel is another way if your suspension was stock. If changing the front shock rebound adjustments to stiffer settings have not showed improvement then your front shocks have not been adjusted to a stiff enough setting yet or are not dampening forces very well, you will like stiffer rebound setting's and a stiffer spring rate to limit stored energy for pitch rotation.
If this does not help then lowering the front ride height or both front and rear will also help you get where you need to be. Lowering the ride height will kill wheel stands by lowering the CG of the chassis and effectively the front mount of the ladder bar at the same time. Be sure for starters that your ladder bars are running down hill at ride height to the front of the car. The more the better for your situation.
Bruce