I converted 789,032 calories to Kilo Joules, and I got 3,301,309,888. I feel like this number is way to big. I set up the proportion like this: 789,032 x 4.184J/1c x 1000 kj/1J. Was this incorrect?

There are 1000 J in 1 kJ.

You last term should be 1/1000.
789,032 x (4.184 J/cal) x (1 kJ/1000 J) = ??