Synpower engine treatment, AKA VSOT was discontinued as already mentioned. Redline Break In Oil Additive is available and boosts ZDDP nicely. 1oz/qt of oil is all that is needed, to boost 700 ppm phosphorous to a total of about 1275 ppm. This is a nice shot of phos especially in an older car with flat tappets.
The name is misleading, according to Redline it can be added as I mentioned to any oil to boost ZDDP levels, so it not only is a break in add, but an additive to boost ZDDP as well.
Maybe this thread should be moved to the oil additives section?
HTH