74-85 12A & 13B 3mm O-Ring Kit (ARE315)
Uses Atkins Proprietary Brown Inner Water Jacket Seals
Atkins Rotary has come out with a new brown water jacket seal, its square cut and seamless. It is impossible to put this seal in wrong unless you twist it on accident.
We had our chemist select the correct materials in order to allow this seal to take an additional 150° over the stock inner water jacket seal. We have also re-used these in our race car a couple times without issue.
See below for kit contents.