OK, wax ring on toilet was leaking so replaced using a Korky's waxless flange gasket kit. I read on several forums that over time, the foam part of the seal can leak which I believe is what has happened to mine. The cast iron pipe coming out of the floor causes the flange to sit about 3/8' to 1/2" higher than the surrounding floor. Because of the higher sitting flange, I had to use toilet shims to level the toilet.

Several forums I've read say the toilet MUST sit flat and level on the floor. In order to accomplish this I will need to take a saw and cut the cast iron pipe down about 3/8" or so. In addition, the floor itself (tile) is not exactly level.

After cutting down the cast iron pipe 3/8" or so, I'm thinking about installing this Oatey kit:

https://www.homedepot.com/p/Oatey-Twist-N-Set-4-in-PVC-Open-Toilet-Flange-436512/100062268

Also, does anyone have recommendations as to what type of saw to use to cut the original cast iron pipe approx 3/8"??