there is no two plane design for stock keggers. There is a center divider in 1996 and earlier, but that is not dual plane. Dual plane completely separates the left and right cylinders.

again, you can use any vac line. If you have the divider, I would do half and half on both sides.

 

to me seafoam and engine restore is like getting radiator stop leak.

All seafoam is, is a solvent that thins your oil, thus changing its composition. You can add 1 quart of kerosene or diesel to your oil and get the SAME effect (non-combustible solvent). The bad thing is if someone prior to you, used 3 cans of engine restore and you have a few "engine restore kidney stones" mixed with some sliudge, they will get caught in your oil pickup, a lifter etc, and bad things happen.