Clark, the #178 is the same box size as the #78, the coupler is one of the whisker types. Would that fit?
Well crap. The 178 is just a 158 in the narrow box. The 78 had the coil centering spring like the old #4 and does seem to be gone. You would have to do some mods to the center stud of a coupler box designed for a 178 to take a 158.
Strange that the 78 has been dropped - it wasn't around that long. I bought some just a few weeks ago for an RYM car. Don't remember where though.
