This brings up an important point. The oil passage drillings may be different on that front cam tower for the M130 motor from your old M180 motor.

Did you use the towers from the old motor?

The oil galley side on the block is on the left (driver's sd), while the tensioner is on the right. I think that oil has get over to the tensioner via the front cam tower; comming in one side, going up to the rocker arm lube tube and also down the other side of the cam tower and back down into the cyl head and to the chain tensioner.

It is important that the cam tower you used has the drilled passage going down the right 'leg' of the cam tower to pump that tensioner up.

Another thing I recall you saying is that you used the cam from the M180 motor. The original cam had drillings in the cam for the lube of the rocker arms. This was later superceeded to the design with the long 'lube tube' with the holes in it attached to the steel brackets on the top of the cyl head. The later style cam had no oil drillings in it.

I bring this last matter up as it could have an effect on the oil pressure to the tensioner if you have BOTH the 'lube tube' and the cam with the oil drillings in it. This would reduce the oil pressure to the tensioner somewhat as these were not supposed to be used together, i.e. you either used the later 'lube tube' with the solid cam, or the older system without the lube tube.

Unfortunately, I don't think the older system would be compatible with the later oil pressure driven chain tensioner.

Another interesting thing I found out is that the ball pins are NLA at MB. They'll sell you the whole ball pin/seat assy for $45 ea, but not longer sell you the ball pins that were about $7 ea. Dismantlers will certainly have them.