I have a D337 on an old tugboat in Seattle and need a new block heater. The existing part shorted out. It has a sticker on it that says HOTSTART ENGINE HEATER CAT C-151 120 VAC 1500 WATT.
Maybe something to go off of.
https://www.ebay.com/itm/283028691538?epid=28020729931&hash=item41e5d31a52:gđ¤rkAAOSwq8FbM7aH&amdata=enc%3AAQAHAAAA0O6NnnhVExS5jMAn8A91YLrDIfl0AuRz6fOY2Paj9ZcHTqQDv%2FXG2u73DLdCZdhoI24QGSRknuTVUf8XR7FdVyZ%2Bqp2ZUCvviizQgU0RZnY35tsDDMs5Lfg%2FwCifbAfC9XZYTgxfgXW51TPSdBmQPEZEreUWuLyG7yfZxZaJzws36uz6TAi5tjZt41uEYwR0ofL%2BWsrQasib72kQAPEhez1Yf043NP9QYe9feQI%2FvQsqeWlH7qMCNvt%2FhUG50liCQysBUl4B%2FhKpiX0CQxXiwyM%3D%7Ctkp%3ABk9SR56Gw_zlYQ
Or here...
cat c-151 Parts For Sale | MachineryTrader.com