yes, a 305 and 350 utilize the same block
The starters are compatible with both engines, just the 350 starter will probably put out more torque than the 305.
A small flywheel needs to stay with the starter that goes to it. You can use either flywheel, and the block should be drilled for either starter.
the pistons are the same diameter. no they are not the same diameter, the bore on a 305 is smaller than a 350
NO the first has 305 cubic inches and the other has 350 cubic inches
Are you asking if the 350 vortec will interchange with the 305 vortec or any 350 with the 305 vortec? The 305 vortec uses a conventional small block Chevy style large starter. The 350 vortec often uses a high tourqe mini starter. You can interchange them. The mini starter is preferred as it saves space has more torque and normally last longer. Now if you're talking older starters interchanging? Some of the older small blocks used a diagonal bolt pattern and different tooth count.
The headers for a 350 and 305 are the same.
no on a 350 it is on the driver side and on a 305 it is on the passenger side
yes it will I've even bolted a 700R4 on a 85 (305)
If the Buick 305 is really a Chevy 305, then the motor mounts will interchange with a Chevy 350.
No they are not.
no
305 is the same distributor as a 350 will even fit some big block chevy's.