An all out conventional war between Nato and Warsaw Pact would be very hard to quantify, without nukes, war favours the defender.
US + WE got more production, but the communists would be more willing to make sacrifies.
Look at the Vietnam war, US killed maybe millions of vietnam people (soldiers+civilians) but if a nation is willing to take losses of millions compared to 60000 that means that millitary strenght will be not the most important factor. Same goes for Soviet vs Mujahedin, the Afghani people could not match the millitary might of a superpower, but they prevailed because of the will to fight and to defend at all cost.
Russians died for their homeland during WW2, but I think that western Europeans also would fight very hard if the soviets came knocking.
Mujahedin got some cool weapons from the US, but Stinger missiles and other nice toys would not have made an impact if the resistence had been much weaker. So the hypothetical NATO vs Warsaw Pact is not only about airforce, tanks and stuff. The power of the will would be what would matter most in the end, imo.