But ask him how old his charming wife is and he comes over all coy. "I've forgotten," he laughs. It seems that one of the few bonuses of enduring the year-long 6,000-mile ordeal was that Long March soldiers found themselves popular with their female colleagues. Mr Zhang, still sprightly in his grey Mao suit and trainers, is worried that it does not sound very revolutionary for a Red Army soldier to have wooed and married a beautiful teenager some 17 years younger, who was not even born when he completed his odyssey.
On every other topic, however, Mr Zhang, sitting in his traditional arched-roofed home in Yanan town, has an impeccable memory. And so it should be. Since he retired because of poor health in 1964, when he was 43, he has been something of a professional Long March veteran, taking to the revolutionary lecture circuit with stories to inspire even China's cynical youth. "My audiences have totalled 7,000 people," he says.
Mr Zhang is in great demand at the moment, because this week the Chinese are celebrating the 60th anniversary of the end of the Long March. As President Jiang Zemin told the country last week: "The Long March spirit is a great driving force that has inspired the Chinese communists and the Chinese people to be indomitable and hard-working."
Behind the nationalist fervour there is an extraordinary story, and a dwindling number of elderly survivors to tell it. When about 90,000 communist soldiers and supporters set out from eastern Jiangxi province in October 1934, the move was a desperate retreat from the advancing Kuomintang nationalist army. Fewer than one in 10 of the soldiers who set out survived to arrive in north-west China a year later. It took another year for the disparate groups to converge on Yanan, northern Shaanxi province, which from 1936 was Mao's base for 10 years.
Mr Zhang was a 13-year-old peasant boy when he joined the Red Army and the Long March. "The most unforgettable thing is that we had nothing to eat, nothing to wear, nothing to use," he says. Thousands perished crossing snowy mountains. "The most difficult period was crossing the boggy grasslands of Gansu. The animals could not go through or the stretcher carts ... We lived on salt, water and roots. We could not lie down, because the ground was wet. The only way to rest was to sit up all night. Every morning a lot of soldiers could not stand or speak any longer. They just died there."
Attacks by the Kuomintang persisted. Mr Zhang says: "During the Long March, a lot of soldiers were killed by KMT bombs, and the corpses and limbs were blown up and suspended from the trees. Whenever I talk about this I feel like crying." But talk he does. Foreign visitors to Yanan are regularly brought by local officials to be charmed by Mr Zhang as he recalls the Chinese communists' greatest hours. He gives lectures to groups of domestic Chinese tourists. But it is what happened to Mr Zhang after the 1949 communist victory which is the most telling reminder of the trials of recent Chinese history.
In the mid-1950s he joined the brigade led by Peng Dehuai, the defence minister. But Peng was deposed by Mao in 1959 for being the only senior figure to criticise his disastrous Great Leap Forward, in which some 30 million people starved to death. The unit was disbanded and Mr Zhang was sent to famine-stricken Gansu where he was branded as having "rightist tendencies". "I was forced to make self-criticisms and sent to the countryside. There was no crop in the fields. So I remembered what I had done during the Long March, and told the ordinary people to dig up roots. A lot of people survived in that way."
How could a Long Marcher have been deemed a rightist? "Because I complained. I said the socialist construction I was taught was different from the reality ... I wondered why the common people had nothing to eat or wear. And I was reported."
This is not a part of his story Mr Zhang will dwell on during the anniversary celebrations as he lectures groups of visiting Chinese. There are apparently a handful of other Long Marchers in Yanan, but they cannot help. "The others are too old. They can't concentrate!" he laughs.Reuse content