I have an 85 firebird with stock 305 and 700r4. When shifting into drive or reverse from either park or neutral, the car seems to jump or buck. It feels cool like its ready for a rip haha but i know it is not quite right. Any ideas on what it could be??

Are you not holding the brake in enough? Could be excessive backlash.

Ya it happens when im jamming the breaks or feathering them. What is backlash? and what would cause that?

Mmk. Backlash, simply put, is how much "wiggle room" there is between mechanical parts. It can get worse and worse as said parts wear down.

Is there any noise that accompanies the jump? Any metal on metal clanking or anything?

It's normal to have a little bit when you put the car in gear, and it will increase if you, for instance, drop a bigger engine in but keep the stock tranny.

There is a clunk when shifting into gear, does not sound terrible or anything but the clunk is there.

Ok, the clunk is normal (in my experience with cars of this era). My "clunk" got better when I changed the U-Joints, but it is still there to some degree(and I have a built TH350). Check your brakes and make sure they are grabbing well and have plenty of pad/shoe left

Mine did that right before my rear burnt up.. Currently rebuilding it now..

All right, i will check the brakes now, and hopefully my rear end is not about to go... Also, i have a turbo 350 with a shift kit and a broken housing i got from a friends 86 camaro 383. Will the guts of the t350 go into my 700r4??

Brake pads and shoes have lots of life left in them, and rotor's look good

No, they will not, totally different.