Does anyone know the clamp size in the below pic. I keep popping my off. Also, anyone know the spacing between the plenum and the intake? Curious if I can fully remove them by sliding the coupler over and squeezing the new/old clamp between the existing space. I really do not want to remove TB and plenum to get to these.

 

This should help.
I'd support and lower the motor to the cross member for a little more access and do new mounts while you're at, it if you haven't already.
Clean off as much oil from the plastic first and tie a string around the new clamp before you try fishing it on there.

 

Thanks. I think the reason one clamp keeps popping off is because of the oil that is on it. Maybe I'll lower the engine, shift the coupler around and clean the oil off first somehow and re-tighten the current clamp.

 

Something is not right. The hard rubber coupler has a groove in it which fits in the groove in the plenum and the manifold. It should not pop off even with a little oil on it if the clamp is secure.

 

Good point, getting those 4 holes and clamps to line up even with engine out is not fun but when it's all together right it is very solid.

Check the lower mounting bracket that ties the two halves together with a small camera/borescope if you can't see it. If someone didn't connect those correct, it will keep the upper manifolds from being close enough together for the grooves John mentioned to seat.

Not the one I bought here, but there are a bunch of choices:

 

Thanks guys. I slide the coupler to the side and cleaned it off. Put it back on and seems to hold boost. I think previously that clamp was no on tight and oil just got between the couple from all sides or it was never positioned over the grooves correctly.

After a semi-successful boost leak test, I found some vacuum lines popped out from around the DV area. I'll make a new thread in couple minutes and hopefully you guys can chime in. Thanks

 

You cannot catch a break...