This was a two-axle chassis intended to be fitted with a single-deck body with a capacity of around thirty seats.

It had a 5.1-litre (310 cu in) four-cylinder side-valve petrol engine, the basic design of which dated back to 1919.

[2] In 1925–26, manufacturers such as Guy and Karrier introduced bus chassis designed to take advantage of regulations that permitted a bus to have a greater length and gross weight, and thus a greater seating capacity, provided that the chassis had three axles instead of two.

The biggest customer for the Model 663T trolleybus was London United Tramways (LUT), which in 1931 bought sixty (all double-deck) of the 89 produced.

In 1937–38, the LPTB bought a further 24 of Model 663, fitted with single-deck coach bodywork – these formed the LTC class, numbered between LTC1 and LTC24.

[22] The engine was the AEC AV590, as used in the Bridgemaster, which had a displacement of 590 cu in (9.7 L) and developed 128 bhp (95 kW) at 1,800 rpm.

In the model codes, the initial 3B indicated a Renown (the Bridgemaster having been B or 2B); the next figure showed the number of pedals and thus the type of transmission – the Monocontrol option had no clutch pedal; the R denoted right-hand drive; and the A denoted air brakes.

[23] The design, like the Bristol Lodekka and the Dennis Loline meant this double-decker could travel under low height bridges, whilst maintaining near-full-height standing room.

Bodywork was constructed by a variety of coachbuilders, primarily Park Royal Vehicles which built 130, but also included: East Lancs (33); Northern Counties (39); and Weymann (40).

Major customers included City of Oxford Motor Services (43); East Yorkshire Motor Services (34); North Western Road Car Company (33); Nottingham City Transport (42); and Western Welsh (28).

[23] After Leyland acquired a 25% stake of Bristol Commercial Vehicles and Eastern Coach Works in late 1965, Leyland had three different front-engined low-height double-deck designs: AEC Renown, Bristol Lodekka and Albion Lowlander.