That's pretty short but not terribly low. I'm no chassis expert, just have made many mistakes on my own. Personally, I wouldn't make big changes. I'd try a longer ic at about the same height, maybe 40-45", soften the rear shocks on extension, and lower tire pressure. I wouldn't be hesitant to try 4.5-5lbs in a 2000 lb car. Mine, with a sbc, spun bad at 6lbs....
My Vette weighs 2180 with a bbc, 30lbs of rear ballast & me. I run 4.8 lbs most of the time and run fairly fast (5.60's @ 125 in the 1/8 and 8.60's @ 157 in the 1/4 at 8000ft) and it drives great at speed.
What brand tires do you run and how many runs are on them? With my sbc, Goodyears were good for about 120-150 runs before they went away. I've heard that Hoosiers die sooner, but have no personal experience.
I chased my 4-link all over the place, and made many other changes with little improvement, only to find out my tire gauge was bad. Seriously, get yours checked and good luck.
Hope this helps,
Johnny