Egr measurment venturi

[PuroCumminsPower]

Can someone please chime in on how to stop air from leaking from the "Front EGR connection tube" I replaced it a couple months ago. Replaced the gasket as well. I rechecked for air leaks by presurizing system like Rawze shows and found a air leak at the Front EGR connection tube. What else could I do to stop air leak?

https://quickserve.cummins.com/rtgraphic...191_lg.png

Its number 6 on diagram. I stripped one of the bolts #5 on diagram. Anyone know the part # for the bolts?