904 and 8 3/4" gasket advice

Hi all, I hope everyone is doing well in this strange time we are currently going through. I have a few questions about my upcoming spring project for my 1968 Barracuda: In a couple weeks here I am going to be dropping the transmission to replace the input shaft seal that is leaking badly and I want to do a couple other things while I am in there. The car has a 1978 360, its original 904, and an 841 case 8.75" axle from a '67 Formula S car. All of this is in preparation for bringing the car from Anchorage, Alaska to Indianapolis where i am currently going to school. The tentative plan is to barge it to Seattle, WA and drive it the rest of the way.

Once I drop the trans, I am going to replace the input shaft seal, the pan gasket (and do a fluid/filter change), and the output shaft seal, as well as the engine rear main seal and oil pan gasket as they are leaking too. My question is about the rear axle; I am going to change the fluid in it because I don't know how long it has been, and I'm sure the 3.23 SureGrip would appreciate it. While I am in there, should I also replace the axle seals? The last thing I want to do is blow one in the middle of nowhere and have drenched brake parts. They do not currently leak, so should I just not worry about it? Is it particularly hard to do?

I'm also wondering if you guys have any addition suggestions for preparing this car for the long road trip that will happen in the future. I'm doing full fluid changes, replacing all the old radiator hoses, replacing all burnt out bulbs, and a few other things for comfort. What are your suggestions?

I think you answered your own question on the axle seals.:D
They are easy to change.

Pump seals do sometimes leak without the converter being cracked just so you know.
You do need to inspect really well while it's out though.