Couldn't narrow my search down to be useful, so here goes.
Who's running 285/55-20's with a 4:56 gear? My question is what rpm are you turning at 65 mph?

 

i have 33"s and 4.56s, kinda wish i woulda went 4.88. rpms are not too high at all. i wanna say just over 2000rpms at 70mph

 

I am, 305/50/20's 31.25" tall, at 65 Im turning 2300rpms

 

what are you getting for mpg at that speed?

 

16.4mpgs

 

I did the caculations and came up with 2200 rpm with 31's. But as you can see there seems to be some real world variations that are not accounted for by just playing with the numbers.
Anyone else out there that would care to share?

 

imo 2200rpms is the perfect hwy cruising rpm for the hemi.

 

Yep you get the best mpg around the 2200rpm mark

 

lol 2200 for me is 85....I'm liking this thread. ill just remind the cop 'bud, I'm conserving fuel doing the world some good. more than I can say for you trying to catch up to me in your furd'. pretty sure he'll let me go

 

I agree, 2200-2300 rpm would be what I am looking for.
4:56 certainly looks like the gear to use.
As for the ford, Just tell'm sorry officer, my wife ran off with a guy who had a car like yours and I thought he was trying to bring her back.