You didn't want to hear this answer :) but most 2008 football teams would beat their typical modern-day opponents - ie. their 1970 versions.

Players are being noticed much earlier now (pro training starts much much earlier, and from a wider pool of talent), and also modern players are (mostly) saints in terms of maintaining their fitness ("healthy food" based in individual medical testing, no alcohol/smoking/drugs - and tested regularly for this) - while as for the 70's players - it's full of stories of late-night partying.