The chassis number for these model its composed of two initial fixed letters which are B & C, followed by a number that can go from 1 to 501 and finally
one letter that determines the series of the model.

Depending on the last letter of your chassis number you can determine what series your car is and look up any modifications done through the range

choose your series

Release dates Car model Chassis number Modification Modification introduced at
 Jun. 52 to Apr. 53  R-Type Continental

 BC1A to BC26A

 Reduced compression height pistons  BC19A 
 Apr. 53 to Sep. 53  R-Type Continental  BC1B to BC25B    
 Aug. 53 to Jul. 54  R-Type Continental  BC1C to BC78C  Commonised cylinder head BC4C 
       Deletion of non-opposed springs in side steering tube BC18C 
       All welded frame BC21C 
       Deletion of reduced friction modifications on steering connections BC30C 
       Introduction of B.VI type gearbox tie rod BC50C 
       Flywheel inertia rings on cars fitted with auto gearbox BC70C 
       Thicker third motion shaft thrust washer BC78C 
 Jul. 54 to Mar. 55  R-Type Continental  BC1D to BC74D  3 3/4" bore engine, compensator pipe between front and rear servo BC1D 
       Strengthened jaws on front brake operating links BC5D 
       Eliminations of chromium-plated servo pressure plate BC12D 
       Flexibox seal in water pump BC35D 
       Long stroke starter pinion BC37D 
       Improved cold starting device BC43D 
       2nd speed start BC47D 
 Apr. 55 to Apr. 55  R-Type Continental  BC1E to BC9E