Underground connection to Cast
 

Adding an addition to my home. In order to connect to the septic tank, I'm going to need to go through the (new) basement wall and connect to the 4 inch cast iron line going to the septic tank ouside (underground).

I've excavated down to the pipe (see picture) and need to know the best way to connect in.

My plan (not sure if its a good one)
cut out section of pipe long enough to fit plastic wye with short extensions glued into it. Use ferkos at both ends of wye to make connection between iron (see drawing attached)