Hello, I think the computer is dead on my '87 300D Turbo and the engine has about 300k miles on it and seems to be pretty tired. I have a '81 300SD engine that needs a new head gasket. I am going to rebuild the head and put the 300SD engine in the '87 300. Does anyone have any idea of any problems I may run into? I like the lack of computer controls on the 300SD and think it is a better engine for the type of work I use it for. I run waste cooking oil as a fuel and the 300SD seems simpler and there is more info and a better supply of used parts for them. Any input would be appreciated. Thanks, Morgan