I understand the theory behind having the blades angled. Most of these lpgs have very little angle about 10 to 12 degrees, not going to make much difference in real use.
With straight blades you can shorten the top link and force the front blade lower to make a uniform depth cut across the entire blade. With angled blades the leading edge will cut aggressively while the trailing edge would be higher causing an uneven cut.
One advantage of angled blades is they will usually leave the dirt or gravel on the trailing edge with very little left on the leading edge side. Much easier to make successive passes with a very smooth appearance compared to a straight blade which leaves a small trail of material on both sides.
The outside to outside (most narrow wheel adjustment) measurement of my Ford 1920 wheels is approximately 60"
I have an 84" King Kutter back blade.
My blade is adjustable from side to side, so I set it to one side - maximum extension..... for driveway grading.
I then angle the blade to the most extreme, or second most extreme, angle setting.
Now I have a blade that extends way beyond the gravel surface of my driveway.
The leading edge of my blade, at the selected angle, is about 18" beyond my wheel track.
It is not fast, but I do find that I can get exactly the grade, and crown that I want, though it takes more than a few passes.
Long ago (now very old) Civil Engineer,.....I am fussy!
An important point for me, is that I do not want my driveway class A gravel migrating to the ditches.
I am able pull it back from the edge, even if I do get a bit of dirt, or a few leaves mixed in.
Class A gravel is expensive! I try not to loose ANY!
I have been using this method for 40+ years.
I do have a box blade, but that is for moving/pulling material.
A land plane ..... is not something I would want! Ever seen anything that looks like a land plane on a road construction job?
A motor grader is the perfect tool for the job, but much too big for a homeowner.
Using a tractor for grading is not optimal, due to the short wheelbase. Front wheels go into a slight dip, blade comes up, front wheels go up a slight bump, blade drops down. I keep my right hand on the 3pt lift control at all times, and anticipate variations.
There are a few old Huber Maintainers (small - belly blade, tractor/graders) still around. They are old (with Continental/Hercules/Perkins engines), and can often be bought at less than $10,000. They are THE PERFECT roadway/long driveway maintenance machine.
BTW: My wife and I never drive in the same driveway track!
A local real estate agent told me my driveway is the best (natural surface) driveway she has ever seen.