[rfmaster]

I had a good luck using SRS Probe pistons for my 350/383 builds with 5.7, 6.0" rods). These are a little bit more expensive than your standard hypereutectic slugs, but can handle abuse or bad gas.

Probe 12340-030 (for 30 over bore)
Stroke: 3.750
Rod: 5.700 ( I would not use odd ball 5.565 factory rods )
Bore: 4.155
CID 400
Piston Volume -15.0cc
Compression Height 1.425"
Estimated CR (will vary depending on deck block deck height, head gasket, etc)
58cc 10.90
64cc 10.24
72cc 9.85
76cc 9.15

A lower cost alternative would be Sped-Pro Hypereutectic aluminum H615CP-30 pistons with similar spec.

//RF