If the Buick 305 is really a Chevy 305, then the motor mounts will interchange with a Chevy 350.
The headers for a 350 and 305 are the same.
No they are not.
the block & heads are the same you just have to pull the 305 out & put the 350 back in
Yes
no on a 350 it is on the driver side and on a 305 it is on the passenger side
yes
yes
305 is the same distributor as a 350 will even fit some big block chevy's.
same as a 350
yes
NO The bore and stroke is different.