250 to 292

[Earlthe3rd]

Hey guys,
I was wondering if anyone can give me some tips or advice on a swap i'll be doing next weekend.
I'll be picking up a 69 c10 that has a 292 with 3-on the tree and swapping that 292 for the 250 that sits bolted to an auto trans in my current 69 c10.
I plan i just unbolting the block from the transmission (which i have never done before) etc. and swapping the motor with all accessories included as the new motor has electronic ignition and a nicer carb setup.

Any things i should try and be prepared for?
will the motor from a standard trans swap seamlessly to an auto and vice-versa?
Aside from new fluids anything that i'll need get that i cannot reuse?
bolts, seals, gaskets?

I am looking for a quick swap, hopefully to get both motors pulled and reinstalled in one day