I know it's hard for younger guys to comprehend but GH wasn't used for bodybuilding in the 70's and insulin was unheard of for making muscular gains. Almost all bodybuilders of the 70's that I knew never would even touch straight testosterone. The some of the commonly used drugs of the day and excuse my spelling was dianabol, Anadrol 50, Anavar, Winstrol, Winstrol V, Equipose, Deca, and plain Durablin. Never heard of anyone using growth hormone from cadavers in the 70's. It wasn't made synthetically till the 80's I believe. It was insanely expensive and also the possibility of being infected with disease. Insulin and Growth was first being whispered about in the early 80's.
One of things about the drugs of today is that they are being made on the black market. Who really knows what in those vials made with counterfeit labels, inserts and boxes? Could be contaminated and the formula changing from batch to batch.
QFT. People are so jaded now that it's impossible to believe that actual weight training and diet, along with the right genetics, can produce a great physique. I'm sure Arnold today would be accused of using synthol on his bicep to get that incredible peak. Many insist that he even had pec implants when you can clearly see that his pecs were always a strong point even in his teens. And calf implants? Even today calf implants don't look even remotely as real as Arnold's real calves (that have shrunk in size with age and no training. Of course, the retort is that he had them removed. Yeah, sure he did).
And even assuming those exotic products were around that doesn't mean it was in common use. Availability, cost, along with the knowledge and desire to use those products just weren't there at the time. OT is right that even Test wasn't used by most bbers at the time let alone being the "base" of all cycles as considered today though it was widely available. When I asked Dr. Walzak at the time about Test he told that the whole point of anabolic steroids was to be a refinement of testosterone where the anabolic properties are enhanced and the androgenic (meant at the time to refer to the male sexual characteristics) were minimized. He believed at the time, as did most, that it wasn't as effective and had more side effects.
I'm sure some, if not a lot, of bbers at the time used Test but it was usually because it was cheaper and available rather than considered more effective but I never knew any that did. And people were pretty open about their use if you were a familiar face and they readily admitted to using Deca and dbol which were the bread and butter at the time but I never heard Test mentioned.