A/C Firewall Template - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SHOWDOG · 08-16-2006, 12:50 AM

I am getting ready to swap a 72 AC unit in my son's non AC 67 Step. I understand I can either swap firewalls (sounds like fun) or cut my existing firewall by using a template from a donor or find someone junking an unusable AC cab and cut and weld that section in. Any suggestion/help would be greatly appreciated.

Thanks,
Showdog

Huck · 08-16-2006, 07:50 AM

Easiest thing to do is to have someone draw the A/C firewall outline on a piece of paper and overlay it on your existing firewall. Mark the A/C design and cut the firewall appropriately. Better solution might be to go to an aftermarket setup eliminating the big box under the hood and a lot of old design stuff under the dash. New systems use a much more efficient compressor, are R34 current stuff, and take up less room. You may have to sacrafice some glove box space but the end result will probable be a lot less expensive.

sneakysnake · 08-16-2006, 10:15 AM

a pic

mrein3 · 08-16-2006, 11:17 AM

They say a picture is worth a thousand words so here goes.

I marked up that template because there seems to be some confusion with it.

The upper hole for the heater core in the non-ac trucks and the upper hole for the heater core in ac trucks line up. The other hole you need to make is marked in the center with a dimple from the factory. To make that hole I suggest you get a "Greenley" punch aka a sheetmetal hole punch.

To make the piece you need to weld in is easy if you have the factory box to bolt on to the outside of the firewall. Just make a trace on the back of that box. Then make a trace on the non-ac firewall. Then use the hole for the heater core that is in both firewalls and line up your two tracings. Now you can draw on one of them the shape of the "J" looking piece of metal you need to make. Cut it out and test the fit on the firewall. Now cut out a piece of sheetmetal and check it once again for fit.

Once it fits nicely grind off the paint around where you are going to weld and weld it in place.

Paint.

Install the rest of the AC stuff.

SHOWDOG · 08-17-2006, 12:59 AM

Thanks for all the knowledge. This is a great site. Your help is very much appreciated. I have contemplated going with aftermarket stuff, but I have a complete system in a 72 parts truck. Not sure which is cheaper in the long run!
Many Thanks to you all!!!

SHOWDOG

08-16-2006, 12:50 AM	#1
SHOWDOG Registered User Join Date: Jul 2005 Location: ATASCADERO Posts: 48	A/C Firewall Template I am getting ready to swap a 72 AC unit in my son's non AC 67 Step. I understand I can either swap firewalls (sounds like fun) or cut my existing firewall by using a template from a donor or find someone junking an unusable AC cab and cut and weld that section in. Any suggestion/help would be greatly appreciated. Thanks, Showdog

08-16-2006, 07:50 AM	#2
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,261	Re: A/C Firewall Template Easiest thing to do is to have someone draw the A/C firewall outline on a piece of paper and overlay it on your existing firewall. Mark the A/C design and cut the firewall appropriately. Better solution might be to go to an aftermarket setup eliminating the big box under the hood and a lot of old design stuff under the dash. New systems use a much more efficient compressor, are R34 current stuff, and take up less room. You may have to sacrafice some glove box space but the end result will probable be a lot less expensive.

08-16-2006, 10:15 AM	#3
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	Re: A/C Firewall Template a pic Attached Images

08-16-2006, 11:17 AM	#4
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,254	Re: A/C Firewall Template They say a picture is worth a thousand words so here goes. I marked up that template because there seems to be some confusion with it. The upper hole for the heater core in the non-ac trucks and the upper hole for the heater core in ac trucks line up. The other hole you need to make is marked in the center with a dimple from the factory. To make that hole I suggest you get a "Greenley" punch aka a sheetmetal hole punch. To make the piece you need to weld in is easy if you have the factory box to bolt on to the outside of the firewall. Just make a trace on the back of that box. Then make a trace on the non-ac firewall. Then use the hole for the heater core that is in both firewalls and line up your two tracings. Now you can draw on one of them the shape of the "J" looking piece of metal you need to make. Cut it out and test the fit on the firewall. Now cut out a piece of sheetmetal and check it once again for fit. Once it fits nicely grind off the paint around where you are going to weld and weld it in place. Paint. Install the rest of the AC stuff. Attached Images __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

08-17-2006, 12:59 AM	#5
SHOWDOG Registered User Join Date: Jul 2005 Location: ATASCADERO Posts: 48	Re: A/C Firewall Template Thanks for all the knowledge. This is a great site. Your help is very much appreciated. I have contemplated going with aftermarket stuff, but I have a complete system in a 72 parts truck. Not sure which is cheaper in the long run! Many Thanks to you all!!! SHOWDOG



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