You have a warranty? Well don't sweat it too much. Twenty percent, if that much, or a reman engine, and install, which is what they will probably be all they pay for, shouldn't break the bank. I just am one in favor of too much engine is just right.
The 572 ci engine, and there is an even larger one out there and a custom built tranny and structure reinforcement and so on would be a nice drive. Not passing fuel stops would not be so much fun though. let the ins handle it. Our extended warranty even pays for motel etc if a wait is involved. :) good luck