What has your mileage been like with the bigger tire? I see that your speedo is not adjusted, but didnt sound like material impact. Are you seeing a significant drop at all?No issue at all the highway ride is smooth. I have a vibration around 48-55 which could be a balancing issue but nothing at highway speeds. I chose this tire because of it's great reviews although I would have picked Ridge Grapplers but didn't want to be in an LT tire. I think you could squeeze more height in there also but i didn't want to alter much.
I have a grey limited on order and will be replacing with 20" wheels (probably +1 offset vs +19 for stock) and thinking the non-LT Ridge Grappler in one of the two sizes available on the 20's; 305/55/20 or 275/60/20 (~33" outside diameter, ~1.5" narrower than 305/55) so somewhat similar to yours. Your info is comparable and helpful so thanks for posting!