Although you do not say so it sounds as if the problem is just at the front. Am I right? If so here are some comments that may help.
If you have increased tyre diameter 3" and are still 2" too low then it sounds as if the car has sunk 3 1/2". This seems an awful lot but is not impossible if the changes have increased weight at the front. If you just reposition the spring base you will still have 2 problems -1 when the car goes over a bump the springs may become coil bound and solid (disasterous handling) -2 The springs are still weak (spring rate) relative to the heavier load they are carrying.
You need someone who can make new springs. Measure the length of the current springs when under static load. If you then take them to someone with reasonable knowlege or a spring rate tester, he will be able to calculate what is needed in terms of rate and free length, to give a static loaded length 2" longer. You may also need to uprate your dampers to a stiffer setting to control the dynamic movement of the heavier weight