Sure, if you run at the stock 4WD ride height nothing is going to scrape.
But I'd be willing to bet that most people are lower than that, whether they intentionally lowered the car or just because the stock torsion bars have sagged over the last 40+years. And the suspension geometry is a heck of a lot better lowered from stock.
Even with the Doug's my headers flanges are at 4" to the pavement. I'd like to go another 1/4" to 1/2" lower, but I'm pretty close to the limit of what I need for suspension travel even with the 1.12" torsion bars.