cutting cast iron

i have a 2" cast iron drain coming out of a poured concrete slap. I need to cut about 1-2" off the top of it to get the new drain to seat against the floor properly. I read alot about cutting cast iron and it seems there are some difference of opinions. I was thinking of cutting it with a saw-zall and a carbide tip cutting blade. The pipe is 40 yrs old. Is this a good idea or should i go another route? I dont want to crack the pipe under the slab.

cutting cast

Plain metal-cutting blade should work fine. Once in a great while I've run into some that is hard as can be so I put a metal cut-off disc in 4" angle gringer and buzz around it.