Rear axle ratio opinion

what is your cruising rpm? probably less than 3000, and a 3000 stall converter is probably actually around 2800. If the converter is slipping too much the trans will be hot. a 3.55 gear will match your cam better, but may not be worth the $ to switch, cuz it is only slightly more than 3.23 . and 3.23 is not the maximum performance ratio, I think it may be considered the best overall average street ratio. I have run a 4.88 gear in my 340 4 speed street and strip Duster for 30 years with 28" tires, 3600 rpm at 60mph, 7200 at 120