I've always used the Eastern Parts strutted pistons, probably made in Japan in the 1980s, and never had problems. Well, except self-inflicted ones from leaving inadequate clearance. The VL pistons are the same as the ULH. Several dealers carry these, from standard to about +0.090 oversize. The only difficulty is they are made to a standard bore of 3 7/16", rather than the actual VL standard bore of 3.422", and thus come out 0.0155" larger than you expect from reading the old Harley manuals.