Hi all,
I'm taking the 302 out of my '85 Bronco, and replacing it with a "carb'd" 300 (Sniper EFI system). As such, I pulled out the ECU and the huge brick of wires that goes through the firewall.
Both the 300 and 302 of this era had an ECU (the 302 was fuel injected, the 300 was computer control carbureted), but the 351 was still 100% carb'd, so it had a rubber plug that filled this hole (so plugs DO exist).
Since I'm removing the ECU, I'd like to fill this massive hole, but can't find a plug anywhere for it.



The hole measures almost exactly 1.5" x 3.00".

Everything I'm finding that looks remotely close says they're either for an EB, or for a 67 - 77 pickup, and measure 1.375" x 2.875", which is too small.
Does anyone know where to find this plug?

Thanks

 

Are those measurements of the actual OD, or where the inside compresses against the sheet metal (as there is slight overlap all around to seal)? Why not call these folks (the manufacturer, not Summit) and see if they have something: https://www.summitracing.com/parts/s...135k/overview/

 

Try Ron Francis Wiring GA-50 Has a hole in the center but is your dimensions.
https://www.ronfrancis.com/prodinfo.asp?number=GA-50

 

This is the inner diameter of the hole, if measured side to side and top to bottom.
Thanks for the link, I'll get a hold of them and see what they have.

 

That looks to be like the one I took out, with the wiring harness going through.
It's a last resort, since it is smaller, but still has a hole.
However, the 351 V8 equipped Broncos didn't have a wiring harness, since they had no computer, so they had a full plug with no hole. Hopefully I can track that one down.

 

I searched for quite a while, with no luck. All, like you said, are the bit smaller one. It may actually fit fine, but you could go to the hardware store and get a .0625" thick o-ring, and slide it in the groove before putting the plug in the hole.

if you noticed the common plug size is only 1/8" small in both dimensions. That means it'll only have a 1/16" (.0625) space around the perimeter of the smallest diameter. I have to think that would work fine, no mods required.

My 96 f350 had a rubber plug on the floor but it's 2" x 3".

 

Well, I found one in the junk yard today. Actually, I found two, but one was completely dry rotted, while the other was still nice and fresh. Both in bull nose trucks with 351s.
Part number is: E3DE-14603-BA
Nothing comes up with a search for that online, but... I have a plug in my firewall now.

 

Here's some pictures.

I also pulled out my micrometer to get the width/height and it is, indeed 1.50" x 3.00" on the gasket inner diameter.