Pistons are ITM brand, which is probably the best after market,
cast piston available for L28 Z cars.  Ive sold dozens of sets of
these pistons with GREAT results.  I use the pistons in a couple
of my track cars, that see 7500 RPM regularly and they hold up
great.  They are a cast piston, but they are VERY well cast.  
They come NEW with NEW Wrist Pins, and New Rings.  The
sets are also closely balanced as well.  Pistons are not available
in standard size anymore, but 1mm and .5mm sizes are stocked.
 Flat tops or dished pistons are available.  I ship them within two
business days and they are in stock.  Comes in a set of 6.  Price
is 275.00 Plus 25.00 Shipping.