I'm not sure if the throttle hang fix will cure a sound like that. You aren't thinking of the 'moosing' problem, are you?
As for where to put the cap, I'm not sure! Your engine is laid out differently than mine. I've got a 98.5 SVT, and have different hose locations.
For me, my '#5' connects directly with '#1'. My cap is at your '#1' location.
Good luck!