md3b vs md17c differences

any volvo guru"s know the difference between the md3b and the md17c. I have 3 of these engines as well as a md2b. I think the bore and stroke is the same...that leads me to believe the block and crank is the same. The rods? The heads i think are different but the difference is made up in the bucket (cylinder). Next, what about the injection system, pumps and injectors. Last year the md3b jerk injection pump quit...one bad cylinder on the pump so I had to use parts from a md17c pump...exactly the same.
Please anyone know the differences.
Of course I have interchanged the md2b and md3b heads cylinders pistons rods and transmissions...but what about md3b and md17c
Mitch

Hi Mitch,

Here's a good website for you:
http://www.marinepartseurope.com/en/default.aspx
You might be able to compare parts by looking at the diagrams and checking part numbers. We carry shop manuals and printed parts diagrams for the older Volvo engines too. You can find them here.