Stop focusing on stuff that doesn't matter.
It's already banging against the limiter that is set too low.
TIRE HEIGHT IS NOT THE PROBLEM!
Too little air, yes!
Too low rpm chip, yes!
Initial timing sucks as it's set WAY too low, yes!
Total timing WAY too low, yes!
Total timing a a car that is driven on the street is a HORRIBLE method. Even drag cars should not be timed strictly on a total timing basis. Initial timing makes a HUGE difference in the way a car runs, especially one with a tight or lower RPM converter.
All real simple to correct and cost almost nothing!
Puas, make a list of the things you want to change, most important to least important and post it up.