Is this a bad idea?

I have a '73 Duster with an 833OD, 2.76 gears and 26" tires. I recently swapped a 5.7 hemi into it and it goes like a bat outta hell. At 80 mph it's taching about 2100 rpm. Has gobs of low end torque. I'm going to swap to 3.23 gears when I put a sure-grip in it.