Running without o2 sensor

[SoguRacing]

Ok guys, i just bought a megan turbo elbow and its for a fat o2 sensor and my redtop has a skinny o2 sensor. Question...What to do...Do I run without an o2 sensor? The car is obd 1 so the o2 sensor doesn't do much though it will improve gas mileage at cruising speeds.
Or..do i weld the skinny o2sensor to the fat bung and hope that it works.

I know there's other options but dont really want to go out and buy a fatty o2 sensor or another elbow to suit my needs. Any help is appreciated. thanks