Oversize pistons, oversize rings

[Andy <adixon@loudoun.com>]

To the collective knowledge of the list,

Oversize pistons with rings are available in .020 obviously for use when 
the cylinders are bored .020 over. As ring are available in .010, .020, .030, 
does this mean they are a substitute for oversize pistons?  If so why bother 
with oversize pistons? (rhetorical).  I guess the real question is, what are 
the pros and cons of just using oversize rings versus pistons.

Andy