First suggestion is that you read the very lengthy DIY/parts list thread in the hybrid forum. This will help you realize that you need to set a goal for the engine before going ahead with the build. The direction the engine is intended to take has a very pronounced effect on the parts list. The only definite is the head (and even then there are 2 castings in North America that you could be looking for), the rest depends on how you plan on going about it. Its definitely not just a matter of swapping the cylinder heads around and even in the most basic of builds can get expensive.
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