Here is a list of GMC ads in magazines that appeared in the 1970s.

National Geographic
1973 Mar
1974 Feb, Jun
1976 Jul
1977 Jan, Mar
1978 Mar, May

Architectural Digest
1976 Jul, Aug
1977 Jan, Feb, Mar, Apr, may, Jun

Readers Digest
1974 Mar, Apr, May, Jun

Popular Science
1973 Feb, May, Sep

Saturday Evening Post
1977 Sep
1978 Mar

1976 Aug
1977 Jan, Feb, Mar, Apr

1976 Aug
1977 Feb, Apr

1976 Jul 12
1977 Jan 2, Feb 20, Mar 20, May 15

1976 Jul 19
1977 Jan 16, Feb 20, Apr 3, May 15

1976 Aug
1977 Jan, Mar

1976 Aug

1973 Points Early 1973 General Motors
1973 National Geographics March General Motors
1973 Motorhome Life August & Others General Motors
1973 Motorhome Life Jan?, Feb?, Mar? Norcold (Orange GMC)
1973 Popular Science Feb, May, Sept General Motors
1973 RV / Van World Sept, Oct General Motors
1973 Outdoor Life Aug General Motors
1974 National Geographics Feb, June General Motors
1974 Readers Digest May, June Union Carbide (23' prize)
1974 Readers Digest Apr, Mar & Others Pepsi Cola (26' prize)
1974 Outdoor Life June Union Carbide(23' prize)
1974 Golf, Ski ? ?
1974 Motor Trend May ?
1974 Trailer Life May General Motors, Zip Dee
1974 Trailer Life July General Motors,TL Newswire
1974 Trailer Life Oct, Nov TL Newswire
1975 Automotive News Apr (24) General Motors
1975 Motorhome Life July Zip Dee
1975 Motor Trend May
1975 RV / Van World July, Aug
1975 Trailer Life Feb, Apr General Motors, (Eleganza, Glenbrook)
1975 Trailer Life March General Motors, (Eleganza, Glenbrook), Zip Dee
1975 Trailer Life May Carter Shades
1975 Trailer Life June General Motors, Carter Shades
1975 Trailer Life Sept Inst Awn

1976 National Geographics July General Motors
1976 FMC July, Aug General Motors
1976 Motorhome Life & CC Sept Good Sam Parks
1976 Trailer Life Jan Arcoa Trailer Hitch
1976 Trailer Life April General Motors, (Edgemonte), Inst Awn, Zip Dee
1976 Trailer Life May, June, July General Motors, Inst Awn
1976 Trailer Life June Browning Labs
1976 Trailer Life Aug General Motors, (Palm Beach)
1976 Trailer Life Sept, Oct Inst Awn, Byco Cooler
1976 Trailer Life Nov General Motors, Inst Awn, Travel Park
1976 Trailer Life Nov, Dec Porta Leggs, Byco Cooler
1976 Archeticural Digest July, Aug General Motors
1976 House & Garden Aug General Motors
1976 Classic July General Motors
1976 Time "Z" July (19) General Motors
1976 Newsweek Executive July (12) General Motors
1976 Woodall's Trailer Travel Aug General Motors
1976 Sunset Aug General Motors
1976 !Southern Living Aug, Sept General Motors
1976 J.S. News Jul (5), Jul (26) General Motors
1976 Forbes Aug =General Motors
1976 Fortune Aug General Motors
1976 Smithsonian Aug General Motors
1977 National Geographics Jan, March General Motors
1977 Archeticural Digest Jan, Feb, Mar, Apr, May, June General Motors
1977 FMC Jan, Feb, Mar, Apr, May, June General Motors
1977 Fortune Jan, March General Motors
1977 Newsweek Jan (2), Feb (20), Mar (20), May (15) General Motors
1977 Saturday Evening Post Sept General Motors
1977 Smithsonian Jan, Feb, Mar, Apr General Motors
1977 Southern Living Jan, March General Motors
1977 Sunset Feb, April General Motors
1977 Time Jan (16), Feb (20), Apr (3), May (15) General Motors
1977 Westways Jan, March General Motors
1977 Classic Feb, Mar, Apr, May, June, July General Motors
1977 Motorhome Life Mar, April, June General Motors
1977 Trailer Life Jan Byco Cooler
1977 Trailer Life Feb Porta Leggs, Murphy Motors
1977 Trailer Life March Zip Dee
1977 Trailer Life April Holiday on Wheels, Porta Leggs, Byco Cooler
1977 Trailer Life May Byco Cooler, Inst Awn
1977 Trailer Life June Inst Awn
1977 Trailer Life July TL Staffers,lnst Awn, New Models LRP
1977 Trailer Life August Zip Dee, Porta Leggs
1977 Trailer Life Sept Inst Awn, Porta Leggs
1977 'Trailer Life Oct Goodyear, Porta Leggs
1977 Trailer Life Nov Porta Leggs
1977 Trailer Life Dec Sanford GMC
1977 Motor Trend Oct ?


1978 National Geographics March, May General Motors
1978 Saturday Evening Post March General Motors
1978 Trailer Life Jan General Motors, Apollo, Zip Dee, Sanford GMC
1978 Trailer Life Feb General Motors [Palm Beach), TL Newswire
1978 Trailer Life March General Motors (palm Beach), Camp a Float
1978 Trailer Life April Carefree, TL Newswire, Apollo
1978 Trailer Life May Carefree (2X)
1978 Trailer Life June General Motors (palm Beach), Carefree, Onan, Apollo
1978 Trailer Life July Carefree, Camp a Float
1978 Trailer Life August Carefree, Onan
1978 Trailer Life Sept Carefree, Tail Lite
197B Trailer Life Oct Carefree, Onan, Tail Lite
1978 Trailer Life Nov Tail Lite, Coke Winners
1978 Trailer Life Dec Onan, Tail Lite
1978 Motorhome Life Jan, April ?
1979 Trailer Life Jan Carefree, Tail Lite
1990 Outdoors June Delco

1977 Rand McNally Guide I Woodalls Directory Motor Camping Handbook (Pop. Sc.)
1977 Sunset West Directory j Trailer Life Directory Recreation Vehicles Directory