The short answer is Beg, Borrow, or steal a hard copy of Harry Pellow's (the Maestro) "Secrets of the inner circle" It's out of print and you'll likely pay a hundred bucks, but it will save you lots of money and heartache. It will answer all your questions and take you by the hand to acheive your goals--financial and mechanical.
Choice of pistons should be determined by the intended use of the engine, with some consideration to your wallet. Valves need to be checked for wear tolerances--so don't buy new till they are checked. Shops on west coast include Rimco, Comp. engineering, Ollies.
Buy "Secrets" now, the book not the CD, which I understand has some problems, but can't say for sure. try
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