1968 GMC w/ NP 435 - Gasket Set

[Willys_MB]

I'm rebuilding a 350 and getting ready to drop it into my truck pretty soon. Before I do that, I'm going to (obviously) remove the existing 327 and transmission together. I figured since I have the transmission out I'd like to put a new gasket set onto it.

Does anyone here have experience with the NP435 and/or know a reliable source to get parts for it? I tried rockauto and found the gasket set in their ford section, but I'm not sure if the differences will create any issues.
https://www.rockauto.com/en/moreinfo...493670&jsn=456

I'm still fairly new to this world, so is there anything else I should change while I've got the tranny out? It ran perfectly before the motor went out, so I'm not sure if a full rebuild is necessary.

Thank you in advance!