I Need a Firewall Grommet Solution

This simple project of replacing a failing relay has escalated beyond my control and I've managed to dig most of the wiring harness out of the car.  Yeah.  I know. 

Anyway...

The Neon has a 3" firewall hole in a fairly inaccessible place on the firewall.  In its stock configuration, it's got one of those built-in grommets on the wiring harness.  The factory wires are pretty well stuck in that grommet - it appears that they're taped through it - so I can't pull anything through the grommet.  The obvious option would be to just get a 3" rubber grommet, pass everything back through, and slide it back into place.  But when I ran the megasquirt wiring way back when, I simply punctured the factory grommet and ran those wires through.  I could pull all those wires back out and feed it all through again, but that seems like a whole lot of work.

Is there a solution out there for some sort of split grommet that will work with a 3" hole?  I found these 3" grommets called "Seals It", but they're a total of 3" so I'd have to screw the mounting ring into empty air.  If they had one that was 3 1/2" OD, I might be able to make that work, but it seems like 3" is the largest they have.  I found a bunch of aluminum ones advertised out there, but the biggest one is 2.98", so, again, I'm left trying to bolt it into thin air.

Any genius ideas?

A 10" length of wide fuel line, split and run around the hole so that the end overlaps a bit?

If access is limited, that may be a non-starter. And it's not the most secure nor longest lasting option. But that's how I've seen people re-grommet a firewall hole that they didn't want to remove the wiring from first.

Carefully cut the stock one from the wires outward and then use some type of s3alant to put it back together?

Also, I found THIS RANDOM SITE

I cannot vouch for them, nor their product. If you end up sending your PayPal payment to a Nigerian prince, that's on you

4cylinderfury's link looks like a Seals-it, which I have used before and would make sense here.

Ah, okay, looking around further on the Seals-It site, I see that they do have a 4 1/2" option.  I only found the 3" one when I looked before.  I'll have to go measure and see if the larger one will fit in the space available since it's shoved in there with the strut tower.

I could try to put the stock one back together with some sort of sealant.  But my modification wasn't really all that great to begin with and it's already torn a bit from where I put the MS wiring through.  That's one of the reasons I'd like to replace it - might as well get it right, you know?

Sitting here and thinking about it some more, though, maybe pulling all the wiring back through, putting connectors on the hard-wired things, and depinning and repinning the DB37 isn't really the worst thing in the world.  I sort of feel like I've put this much effort into it, why not go a little bit further?

Maybe this?

In reply to Dusterbd13 :

I actually like that style a lot, but I haven't seen one that's big enough for my hole.

(giggity).

It sounds like you already have a solution here, but this could also be a good job for a 3D printer if you have one. Get some TPU and print that inside of a PETG ring. You could make it a split setup if you wanted, too.

The right thing to do is to pull the wiring through, neatenate it, run it through the factory grommet.

Or, if you are lazy, slit the grommet, run the wires through the middle, then tape the sleeve back up after everything is in position.

Yeah...  That is the right thing to do.  And to replace all the hardwired things with actual connectors.  So I've pulled the stock harness, the megasquirt harness, and my other wires all the way back through.

I still need a grommet, though.  The 4" sealsit won't work, because of the placement of the hole.  And all my searches for a 3" grommet bring me back to ones that have an aluminum ring that is 3" in diameter.  Which would just fall through the hole, of course.

https://www.amazon.com/dp/B0DDC9B94M?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1

I got one of these to use for a steering column seal. It might work here

Split CV boot cut down to the diameter you need? https://www.amazon.com/Bailcast-CVS18-Universal-Constant-Velocity/dp/B0080DLLIY/ref=sr_1_3?sr=8-3

Could you just cut a piece of aluminum or steel into a 3.5" OD, 2.5-2.75" ID ring, rivet and seam seal it to the firewall, then use one of the 3" grommets?