| January | — | 080 250 | Distributor drive shaft bore cut 5mm deeper, drive shaft now has thrust shoulder |
| January | — | 080 657 | Fan pulley reduced to 1.75:1 ratio (6.8� instead of 7�) |
| February | — | 080 770 | Exhaust clips have self-locking nuts |
| April | — | 084 089 | cone shaped countersink for pushrod tubes |
| May | — | 084 245 | modified exhaust valves |
| May | — | 085 625 | thicker pipes on exhaust pipes 1 and 3 |
| June | — | 086 726 | pushrod tube seals now a white plastic instead of rubber |
| August | — | 087 221 | heater boxes now crimped together instead of screws |
| October | — | 089 061 | flatter exhaust valve heads |
| October | — | 090 067 | intake manifold preheat tubes thicker |
| October | — | 090 886 | steel gasket between crank/flywheel, conical sealing surface |
| November | — | 091 879 | crankshaft big end journal 4.5mm radius instead of bevel |
| November | — | 092 265 | oil filler gland nut now taller |
| November | — | 091 357 | thermostat temp lowered from 75-80� to 65-70� C |
| December | — | 093 624 | crankshaft now has oil drillings on reverse side |