Well - my tractor is very close to the size and weight of the OP's. Roughly 9000 pounds without the rear blade and 10,100 with the rear blade.
My driveway is a mile long gravel with just enough fines that it "dries out" about this time of year and becomes hard as 30 year old concrete.
I have an excellent Land Pride RB3596 that weighs 566 pounds and is perfect for plowing snow in the winter.
In the summer when my driveway hardens up - its an amusement toy - drive down the driveway after sunset and watch the sparks fly off the blade as it bounces down the driveway behind my tractor.
Even with my Fit Rite hydraulic top link I can not get an angle that will make this blade cut into the surface. Several posts suggested that I NOT add weight to the Land Pride rear blade for fear of over stressing the frame.
Soooooo - - I bit the bullet and went for a truly heavy - and expensive - rear blade. I had to do something because my driveway needed serious work on the ditches and crown.
I bought a Rhino 950 rear blade. Its a 96" blade - weight is 1050 pounds and I chose no hydraulics. My one rear unit is used for the hydraulic top link.
There is ABSOLUTELY no question about what is going to happen when I lower THIS blade on my driveway. The beautiful thing is how much control I have over the cut and depth of cut. The weight keeps it down without any jitters, vibration, waffling, washboarding etc, etc. I do have to be careful - if I make to aggressive an angle and simply drop the blade - it will cut and go down, down, down until you are no longer moving and all four are digging.
With the Land Pride I'm able to "nudge" it into place to make 3-point connection. With the Rhino - thank God for my 3-point arm extensions. Even with my big 'ol pry bar I'm unable to "nudge" this monster anywhere.
Now the great part - - The Rhino 950 without hydraulics was - - $3295 when I bought it last year(2017).
My only regret - - I should have bought the Rhino in 2009 when I bought my new Kubota rather than hoping that the Land Pride would do the job in the summer.
View attachment 559961 This isn't the best picture - its the only one I can find in my fantastic picture filing system - at this moment.