To find IH part numbers on the NAPA sight go to http://www.napaonline.com
On the left side of the screen click on advanced search
When is asks if you are looking for a specific vehicle, click NO
Enter the IH number in the part number search line (no spaces and click on Interchange button under part number and then search
385703r92 steering shaft oil seal on cub shows NOS 8660, which is the one I put in the 48 I rebuilt this summer
Super A head gasket 301366r1 shows FPG 7732S
You can either order on line, or take that number to your local NAPA, and they will think you are the greatest customer they have.