Ok that makes a big difference! Always worth specifying this in a question of this nature

It certainly makes the earlier flight much less risky. I still woulnd't risk the later one if I were you. But as another poster said above, the question is what is your backup plan if it goes wrong, i.e. if the AMS-LHR is majorly delayed or cancelled. That can certainly happen, be it weather or other causes. And AMS is one of the likeliest rotations to be cancelled because there are multiple frequencies.

If you're comfortable that you can manage the hassle and cost of missing the flight even if that's on balance unlikely, then the risk is worth taking. But you need to know what your options are in that case.