Ask around for someone wanting a set of 3.54 for the 4.10 they have now.
With luck the rear brakes will swap easy.
This may be a no cost option just a day of work.

 

If you have a D80 rear I'll trade straight up for my 4.10s. I have a wanted ad in the classifieds for 3.55s or you can just email me.

In all honesty, the 4.10s and 315's are still a bit slow for a manual truck. With an auto, it should be just about on the sweet spot with 4.10s and 35's.

brnadon.