I believe all of the part numbers listed match the boot kit for my '87 928S4. The boot itself is not numbered separately so you would need to check, but if it's the same then you can get the whole kit from
928 Specialists for $15. The kit includes a boot, both clamps, the grease and an end cap.
The end cap doesn't match so it's a throw away part, but going from around $200 to $60 for all four boots....I'd be willing to toss it.
