Goldilocks:
Your H3 diffs are too small;
Hi-Mo's fire-breathing brakeless H1 is too big;
Time to try the one that's just right - H2
Brakes; diffs, they've got it all (excepting the tie rods).
Just kidding.
Sorry about the road-trip difficulties Hi. I bet he was tired. However, isn't this the perfect opportunity to get a locking rear diff for the Sass-mobile???