Hi, JohnnyL.
That notion of keeping the blade low has less to do with torque than it does with machine balance and safety. If you keep the blade low when reversing up hill, you have it closer to the ground if you do need to drop it in a hurry and it is also hanging more of it weight down from the push trunnions instead of being up high and acting through leverage around the front idlers to lift the rear of the machine off the ground.

Just my 0.02.

I have always wondered what is the optimum size Cat for farming sidehills. I have pushed the limits with D2 and D4 and found the D4 much more stable. My only experience with a larger Cat was a full dress cable 9U clearing brush on a slope formally farmed with horses. I found it grossly clumsy and underpowered. I know they run 5's and 6' s in the Palouse. I once visited a farming operation where they ran 3T D7's but their slopes were mild.. I believe the D7 came in standard width only.

Nothing like time in the seat, but Deas can save some of the new comers a few week of seat time. Not that others do not have a lot knowledge to share, but Deas is generally very easy for me to understand.

I have not spent much time on tractors bigger than a D6, but up to D8's have been used in this area very successfully. Many things like the condition of the soil determine how stable you are on a mountain. But personally the D6 size seems the most comfortable to me.

As per 8c 361 all the D7's are wide even if they are technically standard.

As per Johnny many of the old dozers had trouble backing up hill as the blade made them nose heavy. With all the weight centered on the idler you loose traction as a good part of the track is not getting a bit in the dirt. I got that education again just a few years ago with 40 years experience. But it was discing a walnut orchard. Not my place but I had disced it before. Climbed it without trouble, but had a D6 with a hardnose for hydraulic blade on that D6 to hold the nose down. With a bare tractor I spun out digging a hole. Got the disc closed and got started in a new track and still spun out again. But the walnut got pushed out in summer, we will see the cheap help does on a Fiat/New Holland with grapes on it. Having a tractor that is balanced to keep the whole track against the ground makes a big, big difference in what you can climb ether forward or backwards.

To expand on the original question about proper engine lubrication on slopes, the D8800 Diesel engine in the 3T you’re running has two scavenge oil pump suction bells, one at the front of the oil pan and another at the rear, which both return oil back to the center sump of the oil pan, which is the lowest point. The main oil pump suction bell is located there, which is what picks up the oil that gets pressure-fed into the rest of the engine. So whether operating nose-up or nose-down, you shouldn’t have to worry about all of your crankcase oil ending up on one end or the other because those scavenge bells are picking it up and returning it to the middle 👍

adding a couple tidbits....every situation will be a bit different...learn to read to room...slow is safe..
- walked down 15 acres, small stuff as it was logged years ago...but creating spears if not cut off clean...i found circles the best...
-didn't have nasty slopes to contend with either...careful please

on my mountain side there are many spots where i can't back up with my D3B or 941B--have to head up them going forward and the steeper ones I can only get up with the D3B which has more substantial grousers

if you are working from the top down you can use the world best brake. the blade if she starts to go bury the blade in the ground.

also you have the weight of the machine helping you push.

Pics show the area just North (couple hundred yards) where I’ll be clearing. One pic looks down from deck towards river, the other looking up from below to the deck. My 3T has a heavy tree pusher extending 6ish ft from blade. Hope I can leave it on and not deter performance. The slope does increase some from pics where I’ll be clearing. 

the tree spear should help you. thats the idea of them get the contact point higher up on the tree so you have more leverage.

Over the years I've gotten pretty familiar with the inner workings of a 3T. As I recall, there are three sumps in that engine, and a stack of oil pumps, seems there were four or five, with a series of flow valves that ensure the pumps that have oil, where ever they are, will supply the system. I guessed that 80 degrees slope, nose up or down, would keep the system full of oil as long as the oil didn't spill out someplace...

Be sure your brakes are working ok forward or reverse. I've heard of Cats that would fight against you in reverse rather than assist as ey are supposed to. Mine did not do that, in part because I had to reline them to get any brake at all on one side.

Lateral stability was pretty good, but if the down-hill side dug into soft ground you could find yourself hooking a knee around the throttle pedestal just to stay in the seat.

All things considered, I think the 3T was a pretty good machine.