Cross training for Cross Country?

I am trying to figure out my training plan for cross country next season. I’m a frosh boy and my pr is 19:07. I want to get to 17:40′s for most of next season. I was thinking about 50 miles of running and about 100 miles of biking each weak. Will this be a good plan or will biking work the wrong muscles for running. Either this or more running and less biking.
Yeah i am not just gonna do easy slow runs to get the mileage up. in the 50 i am counting speed days and stuff. And where i live i can’t run a mile without hitting a hill. On my normal routes there are mile long hills with 10% grades. (where i do my speedwork)