John, spreading gravel with a CC and front blade isn't easy. Takes a while to do, and yes, going backwards is the key, just like when using a big blade. If you have a long driveway, it's better to use the tractor. I've spread a lot of gravel with mine, and maintained some driveways for me and others with it, but it is a lot slower than a big tractor.
I have ran those narrow ag tires before on several tractors. Never had a major issue with spin unless it was pulling a plow. I promise, you don't need 2-300# of weight to make a difference. #100 will make a lot of difference. #150 is better. But on those 4.5" rears, it doesn't take as much. Chains make a big difference on snow.
Don't drop the pressure below about 10#. On a bias ply tire, it will split the sidewalls. BTDT. You should know that from the big tractors. Might get away with 8#.... but 10 is about right. The tread should pretty well sit on the ground. Oh, a bit of the corners might be just a tad off the ground on concrete, but that's it. But no "squat" like a radial.
Lew is right. Rear blade is better for gravel. Or in his case, a rake.
Show off......
