Yes, you can use a 305 engine on some boats however, you need to provide more info on the type of boat. Putting the engine on an inboard/outboard, style boat would not be difficult at all, as long as you already have a good lower unit, same goes for an inboard. An outboard, on the other hand will be difficult, if its even possible to run a horizontal engine vertically.
yes
== == Upgrade your gas. Use premium grade, that will eliminate the knocking.
no
Yes you can it is the same engine. Just be sure to use the truck exhaust manifolds.
Your question is a little vague, so im assuming you're asking which is better between 350 and 305 heads. Many people will tell you it doesnt matter. I think if you have a 350 engine then you should use 350 heads. the 305 heads will have higher compression, which will make the car louder, and somewhat faster, however, if you use 305 heads on a 350 engine then you should use a high octane fuel, so it will be better on your engine. Only use 305 heads if you know what your doing. if not you should probably stick with 350 heads. i hope that answered your question.
absolutely. unbolt from one car and bolt into the other. exhaust and fuel lines may differ slightly. use the ones in the car the engine will be used in.
Depends on the size of the engine in the boat.
Engine, not motor, and, while not impossible, such a swap would cause a lot of problems, not the least of which would be the car engine not being protected against saltwater corrosion.
40 weight
When you say boat battery if you are referring to a Deep Cycle battery as used to power a trolling motor then no, it is not suitable for use in a car. However, if you are referring to a battery in a boat used to start the engine and it is not a Deep Cycle battery it will work just fine in a car as long as it fits the battery holder, can be strapped down, and the battery posts are orientated correctly.
what is a good engine oil to use in my car
What engine is it in? 305/350 V8s use 5L of 5w30 in the winter and 10w30 in the summer