A833 - are they usually a hard box to drive?

Some days when it's hot if I want to go from 1st to reverse for instance _ nup not gonna happen. Only way to do it is turn the car off jam it in reverse turn the car on & away I go. That sux.

Reverse has no syncro.So oil type has no effect on this gear.If it wants to grind while attempting to engage reverse, then the inputshaft is failing to come to a stop. Or if you wait too long and the shaft has in fact stopped, then occasionally the straight cut gears have landed nose-to nose, and you have to either "jam it in" or give it a little pedal,while putting a little pressure on the stick.
Now as to the input failing to stop, here are the possible reasons for that; 1)Insufficient plate departure(not enough disengagement), or 2) a crooked departure,as in bent disc,or faulty pp,or 3) shaft dragging in crank.

Finally, if the plate departure is good, then we move to aligning the Neutral Gate and securing the levers onto the studs. This is the number one trouble spot. The nuts come a little loose and then the external levers start to round the corners of the internal levers, and then setting up the neutral gate becomes impossible.Short of replacing parts, I have found the best solution to these rounded corners is red loc-tite.The hard part is not getting that stuff where you don't want it. It absolutely must not find it's way between the cover and the internal lever, and it wants to desperately wick its way in there.In the past, with the cover on the box and in the car, I have tried two methods; 1) was to apply sewing machine oil into that space and allow it to wick into there, and wipe off the access, and 2) was to apply a thin coat of RTV sealer over the area, and let it dry.Both methods worked for me.Next is to get the loc-tite to fill the voids between the levers and the indexed shoulders. I pre coat all the surfaces involved,including the threaded stud, and then correctly install the lever and the special serrated nut.(BTW; this nut has a built in flange. On that flange you will see a series of radially oriented serrations. These bite into the metal levers, better than any loc-washers, and press the lever down flat onto the stud.If the nuts have been allowed to operate loose, then the serrations lose their sharpness and they will no longer hold their torque.Do not be tempted to replace these with regular grade 5 stuff.The grade 5 stuff will not hold it's torque. The loc washer will fail, the flat washer will squeeze out and the threads in the nut will pull out,not necessarily in that order. Loc-tite will prevent the grade 5 nut from backing off but will do nothing for the washers, and the levers will work loose again, and you will be back to square one.Except now you have the loc-tite to deal with.If your serrated nuts are MIA, try to find the correct replacements, or use grade 8 or better parts.) Then I back off the nut a couple of turns and drizzle a bit more loc-tite in there. And finally tighten the nut. The access loc-tite will squeeze out the back, and run down the the back of the lever or maybe the cover. Wipe up what you can. Do both like this; the 1-2 and the 3-4. Give it a half hour, and come back. Make sure it shifts. Repeat in an hours time. Do not use the nut to shift it, use the outer lever and a crescent wrench. Once this is dry,it will not work loose for a very,very, long time. Then reinstall the shiftrods and set up the neutral gate.

Oil is a preference, except as mentioned, do not use synthetics. In winter ATF works well. In summer 80/90 works well. If the brass rings are set up right, ATF is awesome.
The gears in this box are big and heavy. In summer the thicker oil can help slow those bad boys down, making it easier on the brass rings. But that same thick oil is hard to squeeze out of from between the brass and the cone; and until it is out, the brass cannot do it's job. So it's a bit of a balancing act. The ATF squeezes out real nice.

FWIW;My all-time favorite shifting boxs from the 60s and 70s were the top-loader Fords. Man, when those were new, they were marvelous.
I remember my first Chrysler 4-spd. It was fall of 70, and I just purchased my second car, a 70Swinger340.I was 17. It had just 11,000 miles on it.It shifted OK, cuz it was new, and it was mine, and I didn't know any better. The following year, my brother in law purchased a 70 or 71 Cougar351 The top-loader in that thing was something else.
Fast forward to the late ninetys. By now I had learned to make the A833 box shift.These boxes can be made to shift like that. Maybe better.I wanna say better, but I haven't shifted a Ford for a very,very,long time now.

So now let's talk about engaging First from a dead stop. The very first question is; does it grind? No is a good answer. Next, does it engage eventually?Yes is a good answer; it means the brass is working. But its having a hard time bringing the geartrain to a stop, So that goes back to plate departure;you need a little more.. A no answer means the brass just can't do it, and there is something wrong in the clutch, preventing it from coming to a stop .
Occasionally the brass works too good, instantly stopping the works, but again landing the gears nose-to-nose, and stopping the stick from completing the shift unless "jammed". Again, a little pedal while pressure is applied to the stick, will move the teeth, and in she goes.
Back to question one; if it grinds,And you know for sure that there is no, NO, synthetic oil in there,then the brass is done, and it's time for a rebuild.