Well the L24 and L26 have the same bore but it might help if you can get somone to answer this question who has fitted a N42 head to an L24 block as i used dished pistons (cause 40 thou over flat tops are so damn hard to find)
It took me around 12 hours to sand the casting marks off and the with a small buff on a drill (from Bunnings) just polish, polish, Polish using some Autosol.
The heat sheild is half of a 50Klm sign that someone left behind while changing a speed zone, so i cut it in half and shortened it and also cut two tabs to bolt to the manifold. Polishes up really easy and is hard to bend. The other half went to New Zealand with my other set of triples as seen in this thread.
http://www.viczcar.com/forum/index.php/topic,4120.0.html