Have you checked The Filling station for parts? They list pistons and timing gears as well as most other engine parts needed. They even regrind cams for $89.00.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD