174/177 supercharged small block, where to start?

I thought Offy made an ugly box like intake for a 318 called a 360 dual port or something like that that looked like it could be milled for a rectangle plenum like the supercharger intakes, but I cant find a pic of a SB version. It was ugly, runners were straight in to a plenum with a single 4 mounted on top. Not good for NA but looked just like a supercharger intake with a 4bbl flange.