forget,
As I recall it, all re engined B707s - 120s and 436s - had the ventral strake for yaw control due to much uprated thrust. The design was for about 12,000lb/eng and the JT3D3B gave about 18,000lb, as did the RR Conway
The designers obviously had a bit of redesign on their collective plate.
BTW they also had a wing glove fitted to enhance their high speed performance. The rudder control package became an engineers' nightmare with the way boost came into play as the rudder deflected.
They sure did wallow at high alt without the yaw damper.
Now, what was this thread about again???