i get my instant gasket from finnings in peterborough for rebuilding the caterpillars although shouldnt need it, the old cats are 30 years old now so its a must or leeks everywhere. i took of and cleaned out an engine oil cooler on a cat d8k 2 weeks ago as oil was overheating and it was full of silicon and instant gasket fucking stuff gets everywhere. sometimes you have no choice but to use it though