To my knowledge there is not one. The FP 60 uses a complex mechanism to set the trigger. Why would you want to go heavier? It does take some getting used to, but it is best to train with the trigger toward mid-range and then decrease it as you get familiar with it.
Neil
You will be surprised at how fast you will adjust. In no time at all, a 100g trigger will feel heavy...and you will be taking the trigger down to 50 grams or so.