I have a couple of questions about the differances between a 6m6 and a 6r7. I am replacing 6M6 with a 6R7

1. The magnito on the 6m6 is set at about 2 millimeters ahead of the 6r7 if you are looking at it as a clock would spin. How should I set the magnito on the new 6r7? Is it the same magnito for both engines?

2. The 6m6 only has one large hose barb on the cylinder head located above the rear cylinder. The 6r7 has two hose barbs...the large hose barb located above the rear cylinder and a small hose barb located in the front of the cylinder head located between the number 7 and 8 head bolts. What do I connect the small hose barb to? What is the small hose barb used for?