Two systems where the published orbital elements describe an unstable system if the planets are coplanar with inclination 90 degrees. Varying the inclination of the outer planet produces systems that are stable for 10
7 years: HD 5319 at 85°, 81° and 80.5°, and HD 7924 at 78°. Also explores moving the ω angle which has large uncertainties for the outer planets
Stephen R Kane "Resolving Close Encounters: Stability in the HD 5319 and HD 7924 Planetary Systems"
http://arxiv.org/abs/1608.02590