I know of that feels. My timing chain snapped once while cruising - but fortunately it was covered under warranty.
However, if that were to ever happen again, I would consider an engine swap as it would be less hassle and cheaper than having to rebuild.
The rule of thumb is to swap for the same engine capacity of course. But if you're thinking of a more powerful engine, i.e. 380 to 420, its a question of whether your tranny is able to take the additional power load without breaking down. In most cases, you'd find that your tranny would have to be replaced too.
I would suggest getting the facts in order before taking the plunge ...
126 tailed by a 203, 129 leading the pack.