i've been thinking about putting 4.10 gears in my 84 some time. it will have a 350 with a crane 278-2 or comp XE 268 cam in it. at 70mph with the OD in a th2004r it would be turning at about 2400rpms. i would think that would be better than 1900 with a 3.23 rear with a bigger cam in it. what do you think?

 

as long as you can deal with your motor running at slightly higher rpms your fine. it will eat a bit more gas not much cuz its only going up abour 500 rpm acording to your calculations. but its based on what your looking for out of the car. Does it see the track at all? or are you just tooling around the street? because with 4.10's traction becomes and issue with these cars.