The TK Bedford was a range of models for various gross weights fitted with a variety of engines during the lifetime of its production. Most models within a weight range offered a limited choice of alternative options. The mid '70s Bedford specification book of alternative engine, gearbox, axle and chassis configuration details was about 2 inches thick. It was a developing range so the earliest offerings were not necessarily available at the end of production nor were all offered at the same time. TK production continued for a while after its replacement, similar looking, TL model was introduced.
Apart from the noise of different engine models, the air filtration, exhaust system, fuel injection equipment and transmission have an effect on what is heard. It is also common for two identical vehicles to sound different. Sadly memory plays a trick or two as well. Probably the most commonly associated with the TK are the 220D, 330D and 466D.
Four cylinder engines fitted were: 200D, became 220D, became Red Series 3.6 litreTurbo, all diesel engines for the lightest models, there was also a petrol 200P. These for gross weights up to about 10 tons
Six cylinder engines Petrol 300P and diesels 300D, became 330D became Red series 5.4 litre turbo for gross weights up to about 12tons. The larger capacity six cylinder 381D became 466D became 500D which became eventually the 8.2 litre Blue series all for gross weights over 10 tons. There was some limited overlapping of options between weight ranges.
Bedford also fitted the Leyland 350, 375 and its development 400 diesel engine into these heavier models before it developed its own 381 and 466 engines and offered the Perkins 4.236 and 6.354 engines in the earlier years of production.
The heaviest TK tractor unit offered featured a Detroit 6V71 engine.