I just dropped my transmission today..I want to replace all necessary things that can be replaced on it before I install it with my new motor...I was thinking the pan gasket and filter..em I missing anything else?

I know you don't want to hear this, but ... when I swapped to my carbed 350, the 350 was too much for my 700R4 and I had to get it rebuilt. With the 305, the tranny didn't slip at all. The second I got the 350 running, on the 1st test run the tranny slipped so bad I wasn't sure I was going to get it 2 blocks back to the driveway. Doesn't happen to everyone, I was one of the lucky ones. Something to think about.

Now - while it's out,

1) have a drain plug installed in the pan
2) definitely a filter change
3) what are you doing for torque converter lockup? the kits all require installation of a new solenoid and internal wiring - that needs to be done now.
4) if desired, now is the time for a shift kit
5) the Vette servos, boost valves, accumulators - whatever they are - that go in the round cover on pass side
6) if your changing rear gears, now would be the time to change the drive/driven speedo gears to match so your speedo reports accurately

Well I am going with a normal 305 tpi motor nothing big..I had already had a shift kit put in it...so I will not be messing with that for sure I want a drain plug on the tranny...and a filter is a must I'm thinking that would be all I would need cause I had a leak before on it it was the pan gasket.

different schools of thought. I yanked my motor and tranny. Engine ran but had high miles and got rebuilt. My tranny also shifted fine but, I sent it out for a rebuild kit as well as new sprag.

It's like health insurance. If you can spring for the $ few hundred then it gives you peace of mind.