Okay, I got it to work. I redrew the base part (inlet) and then I redrew the rib cross section. I extruded / Boolean diff / array circ. / Boolean joined.
I still had trouble with the Boolean diff.. The first time it didn't work. I tried it again but reversed the order I picked the solids and it worked.
Still not sure all is right ... but it looks good ... lol

Thanks for your time.