u/acuts

I am about book tickets from Pisa (IT) to NYC via Heathrow. I found tickets for a very good price and they have 1h20m layover on the outbound journey and 1h15m on the way back. It’s very tempting as I hate waiting in the airports but I also understand it might be very tight with a long haul flight. Any advice on this? Should I try my luck? What are the chances of missing my flight in either leg of the journey?