I just replaced an older compool 3 way valve with a new Pentair valve. They looked essentially the same. When I went to mount the actuator I discovered that the screws used on the new valve have a different thread. I have the original 4 longer screws that hold the actuator to the valve. The original screws are 1/4-20 thread. The new screws are a self-tapping high-low thread that I had never seen before. A local fastener place suggested that I run a 1/4-20 tap into the threads and use the old screws. Before I realized the screws were not the same, I started to thread one in and it seemed to go in but was tight. Can I use the old screws? What about the tapping idea? Where can I get the right screws? I see packs of 4 for $12-$20 but I don't know if I will get the same longer screws I already have. Thanks.