The following is a summary of Cylinder head changes. The data on this page was taken from Ford Motor Company "Record of Change" forms (releases). The pictures are of parts removed from cars by club members.
| Date | Factory Number | Change | Photo |
|---|---|---|---|
| 12/11/08 | 401-BR Cyl Head | Adopted | PHOTO |
| 12/29/08 | 401-BR Cyl Head | Changed screw hole from 25/64 to29/64 | PHOTO |
| 03/23/09 | 401-BR Cyl Head | Added for use after 1st 250 cars | N/A |
| 12/06/20 | 401-BR Cyl Head | Obsolete - "all stock scrapped in June" | N/A |
| 02/01/09 | T-401-C Cyl Head | Adopted | PHOTO |
| 02/14/10 | T-401-C Cyl Head | Removed spotting boss from rear end | N/A |
| 03/14/11 | T-401-C Cyl Head | Increased compression space by 3/32 inch | N/A |
| 07/22/11 | T-401-C Cyl Head | Added spotting boss to rear end | N/A |
| 04/16/12 | T-401-C Cyl Head | Added "Made in U.S.A." to this piece. | N/A |
| 06/10/12 | T-401-C Cyl Head | Added bosses between combustion chamber and water jacket for 1/8" pipe taps on left side of head. | PHOTO |
| 11/26/12 | T-401-C Cyl Head | Removed 1/8" pipe taps for priming. Bosses remain. | PHOTO |
| 07/17/14 | T-401-C Cyl Head | Added 3/32 to bottom of head, increases all top to bottom diminsions and lowers compression. | N/A |
| 05/17/17 | T-401-C Cyl Head | Redesigned - High Head-Changes ASAP, Use Up Old Stock | PHOTO |
| 08/15/17 | T-401-C Cyl Head | Added 3/4" cored hole between chambers 2 & 3. | N/A |
| 02/23/18 | T-401-C Cyl Head | Changed rear locating boss from 5/8" square to 1/2" | N/A |
| 09/25/18 | T-401-C Cyl Head | Reduced height of combustion chamber 1/16" | N/A |
| 01/12/20 | T-401-C Cyl Head | Removed rear locating boss | N/A |
| 05/18/26 | T-401-C Cyl Head | Reduced Height of combustion chamber 3/32 | N/A |
| 06/22/26 | T-401-C Cyl Head | Increased height of combustion chamber 3/32. | PHOTO |
| 10/20/26 | T-401-C Cyl Head | Specified paint with M-124 | N/A |
Many thanks to Gail Rodda for supplying the pictures, and Trent E. Boggess for supplying the Ford Motor Company Research on this page. Thanks also to the following club members that supplied the parts that were photographed: Kim Dobbins, Don Shanabrook, Ernie Brown, Don Pendock and Gerrit Ritsma.
For more information of the identification of Model T Ford parts refer to The Model T Ford Parts Identification Guide, by Gail Rodda.
