Swapping gear with out hurting things

So I have a question about swapping to a higher gear set.

I currently am running a 727, 8-3/4 rear with 3:73 gears and a 2800 stall converter

I was thinking of keeping the 3:73's for fun street use and using my spare center section as cruising gears. I have a 741 housing with 2:76 gears (or what ever that factory set was) and I believe I can buy 3:23 or 3:55. What is the lowest ratio that you guys think I can use with out causing a ton of heat build up and damage to the converter due to slipping?