I am replacing the head gasket on my Universal 640 DTC. This is a romanian built tractor same thing as a Long brand and the engine is a 60-70 Hp four cylinder Fiat diesel with two heads. It is my understanding that this is the same engine used in a White 1370. I have been told to grease the head bolts before I put them in and tork them. What type of grease should I use. Anybody else work on these engines and have any advice/tips?