I'm not sure Russian life expectancy fell that much - from what I can tell, around 1940 Russian life expectancy was about 35 for men vs 41 for women, compared to 57 for men and 71 for women in 1994 at its lowest point in the 1990s.

However, Russian life expectancies did drop significantly, probably to their lowest points since the 1950s. I talk a little about Russian demographic statistics in that period here - there were some long term trends and significant health factors that combined with the social and economic turmoil of the 1990s to cause such drastic changes.

While you wait for a more complete comparison between Russia and China, you might be interested in this comparison I wrote between Russia's and Poland's economies in the 1990s. One thing I would note as a major difference is that while China in the 1990s was very interested in economic liberalization, it was not as interested in political liberalization. In contrast, the Soviet Union under Gorbachev moved much faster towards political liberalization than towards economic liberalization - Gorbachev in fact was more interested in a more open and transparent political system as a means to revive the socialist economy than he was on building a market economy as such. His reforms ended up being not quite one or the other (and pleased neither the people who wanted more change or less), and ultimately precipitated the political and economic collapse of the USSR. By the time power in Russia was formally handed over to Boris Yeltsin, who began economic liberalization proper, the political and economic situation was already very different from that facing China.