Hi Ray, I seem to recall reading an article or web page about Syncrovest and, if I recall correctly it was basically an earlier version of Twinvest, which is covered in the 2nd, 3rd, and 4th editions of AIM.
I have all editions of AIM, but not the first printing of the first edition, only the fourth printing in 1980. The original was in 1977.
Syncrovest was in 1974 and, as I recall, not all that different from Twinvest. The calculation process was somewhat different but I don't recall exactly what was the key difference, alas. And, alas, we did not have the Wayback Machine in those days so getting the details requires the book but I don't think what one would gain in reading it is worth $50. Of course I could be wrong!
Best,
Allen
