OK I stand corrected it is an LT1 engine.
Here is a link to one of these dumpers:
http://www.classicmachinery.net/forum/viewtopic.php?t=11969Depending upon the age of the engine there are two injector styles (early engines have a single spray pintaux nozzle, and later engines have a long stem nozzle). Injector styles are not interchangeable unless you swap the cylinder head as well.
PM me your contact details and I will put you in contact with someone I know who has a load of NOS Lister LT spares.