This one I have circled. It is a tee that one side has been taped off.
If I canít figure out what goes there, (if it is anything at all), I will just replace the tee with an elbow.
I suspect it is causing me a hesitation problem.
When I give it throttle from idle there is a slight hesitation before it revs.
I have had the car one week, it was running pretty rough when I got it.
The previous owner said a friend of his who builds race Mustangs had rebuilt the motor 10k miles ago.
From the looks of the visible gaskets he appears to be telling the truth.
So far I have cleaned MAF, throttle body, EGR, IAC, replaced air filter, fuel filter and ran sea foam through.
It is running tons better but still the small problem.