OK, first, you didn't say where you are or what your dirt is like. If you are in NewMexico dustbowl talcum powder, get whatever you want.
A disc harrow isn't what is suppose to make a finished seedbed. It breaks up the roots and clumps brought up by a bottom plow. It is only going to make the clumps smaller, very few people plant in this condition, but I know potato growers that say the seeds like it more than a proper seedbed. For that your disc-ed ground needs a follow up, spring tooth harrow, spike tooth, rolovator, cultipacker, something. the poor or cheap truck farmers around here used to put a chain on both ends of the back of the disc, and bolt or weld a 2 or even 4 inch pipe as wide as the disc to tumble that low spot you don't like. These easy adjust harrows can't make everyone happy, but I am glad I got mine. I got others, but none as handy-in general- as the Dearborn/MF 3 point one.
Now, a 165 is a nice beast, but not a sci fi transfomer. A bit wider-10'?, harrow would be max- for long term safety of the machine. But anything bigger than yours isn't going to be 3 point is it? so you need remotes, tires, turning radius of a footbal field, and more brain power involved getting it organized in a small patch, which is all I deal with.
And- hate to admit it- more of a problem in the bigger newer Massey's, but the splines in the drive train aren't indistructable, you don't match the torque, speed- @#$%^ bumps, you are tearing up a little shaft and tearing into a big project.
A diesel? So it is a Perkins, and Cat is cutting production of old Perkins replacements, so you're best off to treat that engine well too.
So in a nustshell? Get 2 pieces of chain a few feet long and an old iron pipe wider than the disc, and your little furrows will disappear on the cheap and easy......
But then again, on this forum... I am always wrong...