86HOGT

I'm putting 3V 4.6 in a Fox and using 99-04 manifolds. I just put the engine in today and thought the hole on the driver side manifold was for the O2 sensor since the 3V manifolds is like that and never bothered to try, oops. It's at least a size bigger than the O2 sensor threads, but anybody know the size by chance before I trial and error?

BTW, anybody wondering, I used Logan Motorsports 3V to 2V flange adapters to use the PI manifolds.

TIA