I ordered a Pace Setter after I rebuilt my 1.6 8v cuz a buddy of mine could get them dirt cheap, but it would not work on the 1.6.
Take this into consideration also, a 4 into 2 into 1 (calmini) is a better performance design than a 4 into 1. Don't believe me, check out some of your local bike shops or sites. There are a few web sites for motorcycle racing that show the horsepower difference between the two. It may only be 1-3 hp difference, but when you are talking about 80hp, 1-3hp more is a noticable difference.