Rebuilt or crate?

[Yellow72C10]

I know this question has been asked plenty, and if there is a thread to help me, please let me know.
I have a 72 chevy 4wd short stepper. Original 350/350. Finally have some real money to throw at it, and a good portion will go to engine and trans.
So the question is, rebuild the current 350, and if so, keep the old qjet? If I did this, I'd have to change it up and add some power later.
Or, get a new crate 350 and be done? Have Anouilh power to turn the tires and not have to worry about a 40 y/o block. Although, can the old th350 handle this?
Any experience is helpful! Thanks!