4A – OEM Type
OEM oil line from thermostat to front wheel well, supply side along rocker. This is the line that is not bent around the jack receiver.
As equipped on ’74-’89 911/930.

4B/4C – Finned Oil Line Specialty Type
Specialty line interchanges with 4A and connects from thermostat to front wheel well, supply side along rocker. Short fins on the tubing surface dissipate heat to supplement the oil cooler. This is the line that is not bent around the jack receiver.
As equipped on ’74-’89 911/930.
This supply line can be used on ’65-’71,’73 with ’74-’89 thermostat and components.
Find complete kits for all ’65-’89 911/930 on our oil cooler kits page.
- More on Finned Oil Lines here…

This part also goes by the following cross reference.
Cross Reference Part Number: