Sullivan tailwheel setups work great. On the 4*60 I used the original setup, similar to the 4*40 and used washers soldered. It has been just fine over multiple seasons and some rough takeoffs and landings on grass. No problem at all. If I were doing it on the 4*40 I would use the original setup and solder washers. Just my opinion of course. I could be wrong.
Dennis Miller