Is there a reference to this motor somewhere on BB?

Here is a story of Craig Coburn taking it for it's 1st run: 122_Canadian's Econo-Power Engine

What you need to get the same MPG is a VPD Economy B20F head with with duals. The stock B20E & B20F have OK inlet ports standard, but the exhaust ports are restrictive. the VPD economy head gets slightly larger exhaust valve & some good porting which frees up some power & a lot of fuel economy.

I'm assuming you meant box stock pistons in your response.

"bog stock" is slang meaning: basic and unexceptional, normal, average.

A carefully built stock bottom end is all you need with a K cam or VPD's SP cam or similar cam from Isky. A pair of HS6 or HIF6 SU in good condition & a decent exhaust. Add the VPD head on top & you get decent MPG.

Here is a link to VPD.