When the B-Series saloon family was updated and substantially re-engineered for the 1962 model year, the Riley version inherited all the changes and was a substantially better car because of them. Like the other four saloons in this family, the principal chassis changes were the slightly longer wheelbase (the rear axle was actually moved rearwards under the modified monocoque), wider wheel tracks, plus anti-roll bars front and rear - all of which meant that it handled significantly better than the 4/Sixty Eight which it displaced.
Not only that, but the engine size was increased to 1,622cc (which meant more power and significantly more torque) and Borg-Warner Type 35 automatic transmission became optional.
Unlike other cars in this range, however, there were absolutely no changes to the exterior styling, for the Riley (like its sister car, the MG Magnette) retained the same chopped-back fins and unique tail-lamps. Nevertheless, BMC did little to promote its sale from 1962 onwards, for they were far to busy with the new generation of front-wheel-drive cars. Production was at a peak in the first year (2,877 in the financial year 1961-62), after which it dropped away to less than 1,000 a year in the late 1960s.
Although the MG Magnette was dropped in 1968, the Riley equivalent soldiered on after the death of BMC until October 1969, at which point the Riley marque was killed off completely by British Leyland.
Riley 4/72 specification
As for Riley 4/68 except for:
Produced: Cowley, 1961-69. 14,151 cars built.
Engine and transmission: 1,622cc, 76.2 x 88.9mm. 68bhp at 5,000rpm; 89lb ft at 2,500rpm. 4-speed gearbox, no synchromesh on 1st gear; centre-floor gear-change; optional automatic transmission.
Chassis: Anti-roll bars at front and rear.
Dimensions: Wheelbase 8ft 4.35in; front track 4ft 2.6in; rear track 4ft 3.4in.
Distinguishing features from previous model: Minor details and badges.
Typical performance: Maximum speed 86mph; 0-60mph 19.5sec; standing 1/4-mile 21.5sec; overall fuel consumption 25mpg.
Launch Price: £1,088
Derivatives: Close mechanical and family resemblance to all other B-Series Farina models; MG Magnette Mk IV was mechanically identical.
Fate: Discontinued in 1969 and never replaced by another Riley.
Source: "The Cars of BMC" - Graham Robson (Motor Racing Publications, 1987)