can be identified by a different chassis number to the production eight-valve model: prefixed ACH rather than ACG, etc. The original engines are also numbered with the format CHnnnHE, rather than the VAnnnnHE format of Dolomite 16-valve engines. Production records at the British Motor Industry Heritage Trust (BMIHT) cover 58 prototype and pre-production cars, all fixedheads, built between February and October 1977. Another car, without production records, is identified by DVLA details, and the possible existence of two more has been inferred from the commissioning number sequence; making a possible maximum of 59 to 61 cars, of which several still exist in the UK and elsewhere. These cars were built at the BL plant at Speke, at the same time as the pre-production runs for the convertibles and TR7 V8s, including a run of about 30 cars built on the line during the factory changeover to the 1978 year model in June 1977. However, it is claimed that some cars at least were converted at Canley from completed TR7s built at Speke. Production of the TR7 Sprint stopped with the closure of the Speke plant. However, the failure of the TR7 Sprint to go into full series production is also blamed on BL's sales and marketing department because they claimed its performance was not sufficiently different from the TR7, though its top speed and 0– time were almost identical to those for the US specification carburetted version of the 3.5 litre Rover V8 powered Triumph TR8. Also, the Sprint engine was unsuitable for the emission-control equipment necessary for sale in the US, which was Sales and Marketing's main target market for the TR7 and TR8. Even so, BL required some, probably about 50, 16-valve engined TR7s suitable for normal sale before the end of 1977. This was for the rehomologation of the 16-valve head to allow the 16-valve TR7 rally car to be used in the 1978 season following a change to the FIA's rules. That the TR7 Sprint was used in this is shown by a series of six photographs in the British Motor Museum's archives, taken on 1 November and listed as TR7 Sprint Homologation. The 16-valve head was approved for use with the Group-4 rally car a second time in February 1978 in time for the Mintex Rally. Converting a two-valve TR7 to the four-valve Sprint specification is relatively simple, compared to conversion to TR8 specification, because