It seems tall to me too...but I'm guessing the weight of a front bumper and a winch and a few thousand miles will settle those front springs a bit.
Looks like a shackle flip may have been perfect for the rear.
If needed he can mix and match spring leafs from a GMT400 3/4 ton truck and use truck overloads which are progressive.
The truck overload is thinner out toward the ends and longer with wear pads, the Tahoe overload is pretty short and consistent in its thickness its entire length so when your down on it, it is pretty harsh.
Installing 64" truck springs is doable, but requires relocating the spring perches on the frame and may not be worth it in the end. However early Pre 88 4wd rear spring mounts on these chassis are an easy way to lift the rear and install the 64" rear springs too.
How long are your front springs eye to eye nojeepshere?