The chassis number for these model its composed of an initial fixed letter which is B, followed by a number that can go from 1 to 651 and finally two letters of which the first one determines the series of the model.

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

(Left hand drive models have an L preceding the last two letters)

choose your series

Release dates Car model Chassis number Modification Modification introduced at
 Apr. 55 to Nov. 55  S-Type

 B2AN to B500AN

 Increased diameter rear engine mounting bolts and modified bracket  B268AN 
 Sep. 55 to Feb. 56    B1AP to B501AP  Modified butterfly valve and countersunk screws, SU carburetter B270AN 
       Introduction of thick washer under fulcrum bracket bolt lock plate to compensate for distortion of lugs on front pan B296AN 
       Steering ball joint castle nuts with increased bearing surface B340AN 
       Front Spring support plate with welded on stabiliser bracket attachment B430AN 
       Modified bosses to increase strength of rear axle tube B476AN 
       Increased friction on brake shakeback stops and increased load on servo return spring B492AN 
       Improved sealing between windscreen washer and wiper mounting and body B492AN 
       Setscrews in place of studs for main bearing caps B39AP 
       Improved water and oil mist sealing on servo B41AP 
       Strengthened spring support plates on front suspension B87AP 
       Modified rear loom to cut out brake light on side on which flasher is in operation B155AP 
       Modified flanges on exhaust fittings B257AP 
       Brake wheel cylinder material changed from aluminium to cast iron B273AP 
       Filter in brake fluid supply tank B287AP 
       Stronger clamps for rear anti-roll bar B341AP 
       Provision of drag links with greater resistance to kinking under compression B383AP 
       Modified type of rear engine mounting B411AP 
 Dec, 55 to Mar. 56  S-Type  B2BA to B250BA  Introduction of aluminium brake master cylinder B20BA 
 Feb. 56 to Apr. 56    B1BC to B251 BC  Modified push button and door handle B158BA 
       Increased number of fixing holes in rear axle tube B198BA 
       Folding arm rests in front seats B210BA 
       Steering lever with taper roller bearings in place of bushes B51BC 
       Strengthened front suspension fulcrum bracket B109BC 
       Modified shakeback stop on front and rear brake assemblies B115BC 
       Dual brake master cylinders B245BC 
 Apr. 56 to Jul. 56  S-Type  B2CK to B500CK  Radiator and drain tap suitable for revised frame B60CK 
 Jul. 56 to Nov. 56    B1CM to B501CM  Modified sealing ring, centre steering operating lever (P.A.S.) B178CK 
       Modified dynamo and voltage regulator B188CK 
       Welded frame stiffeners on each side of jacking bracket B218CK 
       Introduction of copper petrol pipes B326CK 
       Reach nut and washer to suit new spot facing of ball and trunnion joint body, output shaft to prop. shaft B352CK 
       Uphill run pipes from twin master cylinders to supply tank B376CK 
       Revised frame (splayed ends) B27CM 
       Reversal of power cylinder mounting bolt (P.A.S.) B262CM 
 Sep.56 to Nov. 56  S-Type  B2DB to B350DB  Introduction of 18,7 steering ratio on left hand drive cars B46LDB 
 Oct. 56 to Jan. 57    B1DE to B351DE  Increased number of fixing holes in rear axle centre casing B122DB 
       Voltage regulator with swamp resistance (H type) B25DE 
       Introduction of oil deflector plate in rear shock damper B249DE 
 Jan. 57 to Jul. 57  S-Type  B2EG to B650EG  Strengthened front shock damper body (introduction of sleeve in mounting bolt bore) B170EG 
 Jul. 57 to Dec. 57    B1EK to B651EK  Stronger front shock damper B316EG 
       Combined inertia and starter ring modified starter drive and stiffened clutch casing B530EG 
       Stronger fulcrum pin axle yoke B542EG 
       New trim pad clips and retainers B544EG 
       Improved propeller shaft centring button B562EG 
       2:1 ratio dynamo pulley B628EG 
       Stiffened cam wheel B41EK 
       Improved type door seals B101EK 
       4-Point fixing of number plate and reversing lamp B133EK 
       Modified rear axle shaft flange B243EK 
       8:1 compression ratio engine B257EK 
       Dunlop P.AS. expansible hose, alternative t Chrysler B375EK 
 Nov. 57 to Jun. 58   S-Type  B2FA to B650FA  Modified stub axle yoke seal B377EK 
 Jun. 58 to Mar. 59     B1FD to B651FD  Stronger drag links B379EK 
       Modified ashtray finisher B389EK 
       Strengthened door hinges B471EK 
       Introduction of shock dampers with increased size end cover studs B555EK 
       Introduction of ‘Roto’ finished pulleys B627EK 
       Introduction of strengthened adjusting sleeve, steering cam D.R.3 windscreen wiper motor B365EK 
       Stronger rear stock damper link bushes B54FA 
       Deletion of idler lever lubrication pipe B136FA 
       Modified rear silencer mounting to prevent burning mounting rubber B338FA 
       lntermediate heater and demister contols B350FA 
       Introduction of 6” drive pulley, compressor clutch ("R.R" interior cooling) B186FA 
       Improved front door ventilator sealing B388FA 
       Wire type clips on propeller shaft grease seal B438FA 
       Improved type rear brake expander wedges B454FA 
       Final type modified stub axles B458FA 
       Twin jet. centrally mounted windscreen washer B472FA 
       Improved propeller shaft seal B352FA 
       Grease lubricated track rods B556FA 
       Improved window channel guides to ease opening in adverse weather B556FA 
       Large diameter rear axle shaft splines B590FA 
       Grease lubricated centre steering B664FA 
       Enlarged shakeback stop slot In brake shoe web B43FD 
       Modified run of hand brake cable B45FD 
       Strengthened front hubs B65FD 
       C.48 dynamo B71FD 
       Introduction of plain washers at each end of pivot distance piece on braking system direct and intermediate linkage B129FD 
       Improves type of horn footswitch (optional) B159FD 
       Replacement of .250” dia. wing and valance plate bolts and screws with .3125” dia. B359FD 
       Modified door handles with button sealing B433FD 
       Sun visor with improved driver’s vision B457FD 
       Free wheeling boot lock, Deletion of check valve In brake fluid supply pipes B513FD 
       Increased capacity boot type refrigeration B579FD 
       Modified window channels to reduce winding loads under adverse weather conditions B607FD 
       Thermal conductor type water temperature gauge B637FD 
       Modified window regulator handle to prevent fouling of trim pad B645FD 
       Simplified starter relav mounting, Special battery lid for export cars B649FD 
 Feb. 59 to Apr. 59   S-Type  B1GD to B125GD   Seal between bearing housing and body front shock damper B35GD 
 Mar. 59 to May 59    B2GC to B126GC  Modified form of front brake shoe link, extended neck on propeller shaft seal B4GC 
       Modified heater and demister connections on radiator B24GC 
       R.L. headlight unit B22GC 
       Modified clips in electric window winder fuse box B118GC 
       Introduction of purolator air filter on cars with interior cooling B126GC 
 May 59 to Jun. 59   S-Type  B1HB to B45HB  No recordable modifications  
 May 59 to Jun. 59    B2HA to B50HA