Working my way through putting gadgets back on the engine (tr4) and yet another mystery. In the photo you see the bottom left oil filter housing stud..The bolt has a shoulder protruding so something must go there or at least used to go there..but what? I've tried to research pictures but yet to find any with anything attached to that stud. The car is an early '63 so Is it maybe something left over from a tr3 setup that's no longer needs to be that long?