Couple questions on 1969 dart

I this for a street car?
My experience was that on the street,there comes a point where low quickly meets too-low.
For me this was about 5.5" as measured at the lowest point at the center of the K-member. It made driving into an exercise of constantly watching the pavement. And this with TTI above-the-steering,headers.
At 6" now, I can ignore the road for the most part. The sills are about parallel with the level alignment rack, to slightly higher at the back., about as low as I could make it and still run 325s in the factory tubs.
It turned out, that for my driving style, and the local environment, the extra 1/2 inch front height made no meaningful handling difference.
Sticky 245/50-15s did however make a huge difference over BFG235/60-14s. The 14s are about 1/2 inch taller(25.1)than the 15s(24.6), making 1/4" difference in the ride-height. The 15"wheels were custom BS Wheel Vintique rallys.