Yes, it is. I just found the following at wikipedia along with the wheelbase specs. I think if it is from a 1996 or 1997 h body car it should fit.
After the demise of the Ninety-Eight in 1996, Oldsmobile created the Regency for 1997-1998, which used the same front fenders and chrome grille as the Ninety-Eight sedan but kept the standard Eighty-Eight body. The Regency featured a long list of standard features including traction control, leather upholstery, dual 8-way power seats with a driver'* side memory function, a dual-zone automatic climate control system, and an electronic level control for the rear suspension. A standard driver'* side Electrochromic outside mirror was standard on the Regency, a novel feature for it'* time. The interior day/night auto-dimming mirror was linked to the outside mirror and dimmed both with the same intensity at the same time. Some of these options, like the 2-driver memory feature, were not available on the Eighty-Eight Royale or LSS.
All four vehicles used the same 110.8 in (2,810 mm) wheelbase and shared an updated version of the H-body. The suspension tuning, interior appointments, and certain exterior trim was used to differentiate the three models.
1992–1994 3.8 L (231 in³) 3800 Series I V6, 170 hp (130 kW)
1995–1999 3.8 L (231 in³) 3800 Series II V6, 205 hp (155 kW)
1995 3.8 L (231 in³) supercharged 3800 Series I V6, 225 hp (170 kW)
1996–1999 3.8 L (231 in³) supercharged 3800 Series II V6, 240 hp (190 kW)