The cast pistons offered by vendors now are a cut down BUICK application. They in no way retain the unique MEL piston dome shape that is required to have this engine series perform correctly.
ROSS RACING PISTONS
http://www.rosspistons.com/index.php
did have replacements (or should be able to make you a set).
Also, the 410 began production in JUN 57 and there was a block modification done around DEC of that year raising the deck height .020" to decrease CR and to eliminate valve interference. They sould have this information when you talk with them. If not, get back and I will post that information so you can arrive at a streetable CR.
There is also a post below this one that a poster has a set of STD 430 NOS pistons for sale (would require overbore). Might save you some money...
