A/C to non a/c firewall difference - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72 Longbed · 11-01-2015, 07:40 PM

Just looking to swap from a/c to heater only and wanted to know if there's a difference in the firewalls

Tdrcreyn4 · 11-01-2015, 07:48 PM

Yes, quite a bit different.

72 Longbed · 11-01-2015, 07:53 PM

Are they major diffeerences and what are they?

48richard · 11-02-2015, 08:38 PM

I changed my cab from non-A/C to A/C a few years ago. Look at post #10 in my thread below, and you can see the major differences.

http://67-72chevytrucks.com/vboard/s...d.php?t=382711

Andy4639 · 11-03-2015, 07:28 AM

Here is the picture of differences.

snipescastle2 · 11-05-2015, 04:49 PM

I have templates I made from an old A/C dash to trace out where the duct ball housing go, if you need them.... I can't remember which size hole saw I used, but it worked great! most of the places you need to drill holes on the firewall have dimples where the evaporator housing attaches. Make sure you grab the flapper valve/spring and the vacuum diaphragm/bracket, as well as the little nylon bearing/nut/pivot that the flapper inserts into the cowl vent when you get your a/c parts, they don't make that part anymore,(at least I haven't been able to find a source for it yet)
Good Luck!
Ben

69Tom · 11-05-2015, 04:50 PM

Quote:

Originally Posted by snipescastle2

I have templates I made from an old A/C dash to trace out where the duct ball housing go, if you need them....
Ben

I could use these if you wouldn't mind PM'ing them to me. Thanks!

11-01-2015, 07:48 PM	#2
Tdrcreyn4 Registered User Join Date: Aug 2013 Location: Atlanta, GA Posts: 702	Re: A/C to non a/c firewall difference Yes, quite a bit different.

11-01-2015, 07:53 PM	#3
72 Longbed Registered User Join Date: Dec 2014 Location: Mansfield,OH Posts: 22	Re: A/C to non a/c firewall difference Are they major diffeerences and what are they?

11-02-2015, 08:38 PM	#4
48richard Registered User Join Date: Oct 2009 Location: Phoenix, AZ Posts: 475	Re: A/C to non a/c firewall difference I changed my cab from non-A/C to A/C a few years ago. Look at post #10 in my thread below, and you can see the major differences. http://67-72chevytrucks.com/vboard/s...d.php?t=382711 __________________ 1971 C10 Longbed, 350/TH350

11-03-2015, 07:28 AM	#5
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: A/C to non a/c firewall difference Here is the picture of differences. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

11-05-2015, 04:49 PM	#6
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	Re: A/C to non a/c firewall difference I have templates I made from an old A/C dash to trace out where the duct ball housing go, if you need them.... I can't remember which size hole saw I used, but it worked great! most of the places you need to drill holes on the firewall have dimples where the evaporator housing attaches. Make sure you grab the flapper valve/spring and the vacuum diaphragm/bracket, as well as the little nylon bearing/nut/pivot that the flapper inserts into the cowl vent when you get your a/c parts, they don't make that part anymore,(at least I haven't been able to find a source for it yet) Good Luck! Ben

11-01-2015, 07:40 PM	#1
72 Longbed Registered User Join Date: Dec 2014 Location: Mansfield,OH Posts: 22	A/C to non a/c firewall difference Just looking to swap from a/c to heater only and wanted to know if there's a difference in the firewalls



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