Plugging an intake manifold

I've got a hole in my intake manifold that I need to plug. It previously held a shaft with some butterflies on it, but I removed that contraption and am left with an opening directly into one of my intake runners.

My plan has been to use one of these expanding rubber plugs to seal things up. Bought one at the hardware store, fits perfect, done deal.

Now though, I'm second-guessing myself. Am I going to end up sucking this thing into the engine, or ??

I'm more discombobulated than usual this week, sanity check please!

I used one of those to plug an unused port in an air intake snorkel once. It worked fine, but it was also an N/A motor.

I drilled it out and tapped for a 1/8" npt plug, it's working for me.

I used a plate JB welded on a boosted Swift for 3 years, never had an issue. Didn't have to remove the intake for cleaning the shavings out from tapping then......

yeah, I was gonna suggest some JB weld as well.

i have one of those expandable plugs on my egr port on my ls1 intake with no problem. i put a little rtv on it for extra security as well as loctite on the threads.

Tap for a thread, use an allen head set screw, apply permanent loctite, screw in. Fits flush, is almost permanent, but liberal heat and an allen head impact driver could remove it if ever necessary. If that's too much work, freeze plugs come in all sizes and work good too.

Bryce

Find a ball bearing that's just a bit bigger than the hole (a few thousandths should do), tap it in with a hammer until just seated.
This is how some carb manufacturers seal external passages in carb bodies.

Is the OD of the washer greater than the ID of the hole?

Appropriate size currency and RTV?

I siliconed a valve stem cap backwards into the hole when I de-double-throttled an FC RX-7, and it lasted... gosh, maybe 80,000 miles?

It's still okay, I just don't use an OEM intake anymore.

Well, I got another look at the plug and realized it's totally inaccessible already. I'd have to take off the intake manifold (yet again) and the fuel rail. Lots of good ideas, but since SkyRender has done this exact thing before, I'm not going to fret about it.

Thanks all!

In reply to patgizz:

The best fix I've seen on the Ls intake is an auto zone plug gap tool and some rtv. Ive done that more times than I care to admit with zero complaints.