The 2nd configuration is much improved, although you could still bob the truck frame to that shorter wheelbase. Have you upgraded from the ratchet straps yet?
What do you plan for the front wheels? The PCD is 5x100? Maybe you could find some steelies that would fit and use a wide low-profile tire to maintain the final drive ratio. Then you could have a reasonably matched big-and-littles.
I'd put the truck rear-end in backward and put a bronze outboard boat propeller on the yoke, but that's just me. =)
Since you like repurposing boats, consider an aerodynamic boat tail:
