It's sure looking like you do. There are a number of threads and comments about how worthless the RB20 is and I bet you haven't read any of them. Do some damn research on your own then act, being spoonfed here isn't a reliable plan of action.
As for engine building advice, you're not the first person to rebuild and turbo a KA, do some research. First, come up with some goals and constraints/budget. Read and ask some people here, find a local engine builder and talk to him, read a book. This isn't that hard.
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