| Part | Manufacturer | OEM Part # | Price | Notes |
| Extension Housing Gasket |
| 4 Speed Hydromatic M20 |
| Gasket | GMO | 8672160 | 8.28 | Contact Dealer for most current part and price information. |
| Extension Housing Seal |
| 4 Speed Hydromatic MC0 |
| Seal | GMO | 23049496 | 8.48 | |
| 4 Speed New Process |
| Seal | GMO | 8673526 | 8.55 | Order Number & Color |
| Overhaul Gasket Kit |
| 4 Speed Hydromatic M20 | GMO | 8672945 | 71.89 | Contact Dealer for most current part and price information. |
| 4 Speed Hydromatic MC0 | GMO | 8672952 | 68.51 | Contact Dealer for most current part and price information. |
| 4 Speed New Process | GMO | NO LISTING | 0.00 | |