You MUST remember that the taller tires are HARDER to turn! So with the same rpm as smaller diameter tires you will have your foot in it all the time.. This will lower the vacuum and cause the POWER system to come into play much more often..
As a standard you will need more rpm at ANY speed with taller tires than with stock tires.
Go with the 4;11'S. <img src="/forums/images/graemlins/smile.gif" alt="" />
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist