Front frame replacement

Hello, my car has been in serveral accidents over the years and been repaired too. But now that I am do the last hu ra on the car. As I was taking it apart. I thought I saw a crack in the frame. Should I replace the frame or try to have it straighten out or should I just replace it??? And how much does the frame weights???? I don't have any bubbies to help with this task. Can I lift the front end with a engine hoist to remove the frame and set the car/engine on jack stands?

To answer the issue of repair a body/frame shop needs to look at this. New subframes are available from several sources, of course the engine/trans must be lifted out of the frame and all the suspension, brake and peripheral components transfered, may not be a job for a dyer without the proper supporting equipment and tools.