Will all the engine component parts off of my 305 (intake manifold,alt,a/c,dist, trans,etc)bolt up to a chevy 350? If not, what is the difference between the Chevy 305 and the Pontiac 305?

 

yes. Pistons, and piston rings are the things that won't swap over.

If the 305 is a newer style, (post '80) and the 350 is an older style (pre'80), then your dipstick will be on the opposite side, so you'll need an oil pan to match the year of the block.
Also, watch the starter, and it's bolt pattern, and therefore the flexplate/flywheel toothcount.

The rest fit very nicely.

 

for the info.It is always appreciated

 

Exhaust manifolds may also be a problem.

If you are asking about the difference between the 5.0 (305) and the 5.0 (307) there is a difference. the 5.0 (305) is a Chevy engine. the 5.0 (307) is an Olds engine. No difference between Chevy and Pontiac 5.0 (305), they are the same and considered a Corporate engine, that's why they are in multiple car lines. Same as the 307, along with all the other GM engines. Some engines are car specific. But there are differences between years.

 

Am I safe in assuming that the same is true for parts if I decide to go with a 327(old or new block)?