Just thought I'd share this. I went to Home Depot and grabbed a rubber cap from the plumbing section, drilled a hole, and stuck a quick connector in it (bolted on the other side). Now I can hook it up to my air compressor and check for any leaks from the turbo to the intake manifold. This is a 4" cap, but it's too big. I think the turbo inlet is 3.5". But anyway, this one worked too, I just clamped it down real tight. I'm also thinking about JB Welding the threads on the quick coupler.

 

I took a pvc cap , drilled a hole and installed a valve stem in it. That way i can add a little air or a lot of air.about 20psi is all i can go before it slips out of the ferco coupler.

 

I used a 4" OD X 4" ID rubber adaptor from Home Depot, fits perfect.

 

Infidel: Got my pieces at Ace Hardware after seeing your picture on a previous post. Thanks for the tip - it worked great. Found a couple leaking connections using it.