Aprilsweetfatsy:
I'm trying to heavier...
The problem with trying to gain weight at breakneck speed is that you will find a road bump that you didn't have time to prepare for.
The more you stuff yourself, the hungrier you'll get. So you'll eat more food. Plus, you'll need bigger clothes faster too. That adds up fast.
This doesn't factor in any other surprise costs such as sudden medical needs (American healthcare is expensive), replacing things you've outgrown or accidentally damaged,ect. Nor does it factor in the stress you'll feel for focusing yourself to reach such a high goal.
70 lbs is 100% doable. But maybe not in record time.