The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - What's the smallest hole size you can use to run GM loom through firewall?

Paul Y · 03-06-2023, 10:08 AM

Following on from my 'where did you mount your ECM' it looks as if I have enough cable length to actually place the ECM inside the truck. Phew!

Question is, what is the smallest hole I can drill in order to pass through the loom to the engine?

I have heard reference to it but, after a quick search, have not found a definitive size.

Anybody care to share what they used?

Thanks,

P.

03-06-2023, 10:08 AM	#1
Paul Y Registered User Join Date: Jul 2013 Location: Essex Posts: 936	What's the smallest hole size you can use to run GM loom through firewall? Following on from my 'where did you mount your ECM' it looks as if I have enough cable length to actually place the ECM inside the truck. Phew! Question is, what is the smallest hole I can drill in order to pass through the loom to the engine? I have heard reference to it but, after a quick search, have not found a definitive size. Anybody care to share what they used? Thanks, P. __________________ Woody's Build - http://67-72chevytrucks.com/vboard/s...d.php?t=658621 If it goes wrong, I blame the Internet...