No 305 heads bolt up different then 350 heads
If they are 305 vortec they will bolt up. However they do not have the same flow. The 305 vortec head has smaller runners, smaller valves and does not have the same heart shape combustion chamber.
Now if you meant the older 305 heads onto a 350 vortce then no they will not. The vortec uses raised runners and the ports will not match. On top of it all the 5.7 vortec has more flow then any other production head. Placing a 305 head in its place would be going backwards.
The heads will fit the block, but the vortec intake manifold will not bolt to the old style heads.
Yes, they will work. but you wont gain power because the little 305 isn't putting out enough flow to keep up with the heads
Yes they will fit right on there with no machine work are problems.
No it Has a different bolt pattern because of the engine size
will a 4.3l vortec starter fit a 305 vortec?
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.
Into the heads only.
It will as long as the 305 is a VORTEC ENGINE TOO.
Yes they will with no problems. They are basicly the same heads, Just different CCs.
The Vortec 327 heads are designed for a larger displacement engine than the 305. While they may physically fit, they are optimized for higher performance. Using them on a 305 may not provide significant gains and could require modifications for proper functionality.
Yes you can. There are a few sensors that are different but after swapping them over it will run. The mounts and bolt pattern are the same. You will certainly be stepping back as far as performance and power goes. Not only does it obviously have fewer cubic inches but the heads lack the flow that the 350 vortec heads have, The 305 Vortec heads also do not have the famous Vortec heart shaped combustion chamber as the 350 heads. The 305 head also has smaller valves and smaller runners. You can also swap the other way and place a 350 vortec in where a 305 was. I have personally done these swaps with no troubles at all.
Because of the 305's small bore, you're pretty limited. Large valve heads (2.02/1.60) won't work on a 305 because the valves will hit the block itself. If it's an older 305, your best bet would be the old power pack 283 heads. They flow better than the older 305 heads. Now, if it's a vortec engine, you probably won't do much better than what it had stock. If you are really trying to go fast, the best thing you can do is junk the 305 and replace it with a 350 or a 327.