yeah, but it might blow a head gasket, i wouldn't chance it
the heads should fit as long as your not trying to put them on a big block
the block & heads are the same you just have to pull the 305 out & put the 350 back in
noNEW ANSWER: Sorry but the above answer is wrong. The only thing that is different on the 400 heads is that they have steam holes in them and it don't matter if they are blocked off by the head gasket. And YES they will bolt right on the 350 block with no problems.
yes just get head gaskets for the 350 not the 327
NO, not even close.
They can if the heads are cracked ,are the intake manifold gaskets were put on wrong when thay were installed. The heads themselves if thay are good heads will not cause overheating. You cannot put the head gaskets on wrong on a small block Chevy engine.
yes
yes you sure can.
No. The 350 has bigger valves. While you CAN put the 305 heads on the 350, (I can't imagine why you would actually want to) you can NOT put the 350 heads on the 305. Because of the 305's small bore, the valves on the 350 heads will hit the cylinder block.
some heads are vis versa
no completely different motor
Yes you can but you will need to modify the bolt holes in the intake manifold. The TBI intake 4 center bolts, 2 on each side will not line up with the heads. Must drill them out just a little.