4.10s

If you didn't blow it up with 3.23s then the 4.10s will be cake for the case.

As to rpms, the 27.5s will call for 3007 rpm at 60 mph with a M/T.That'd be almost like driving in third with 3.23s, which calculates to 3316rpm.
That's too much for me....... but I'm getting on in years,lol
I gotta tell you though, 2.66 x 4.1 = 10.91. That's a generous starter gear for a motor that puts out 440ftlbs. As a streeter and on a daily basis, you will be spending an awful lot of time shifting, especially the 1-2. I hated it with 4.30s.
Consider also what the rpm will be at your typical city driving speed. For instance; at 30 mph and with 26.5 inch tires, your current rpms with 3.23s are 2360 in 2nd , and1720 in third. With 4.10s it will be 2995 in 2nd, and 2184 in 3rd. Somewhat obviously, you won't be cruising around at 2995, so, Notice that you have traded a nice 2360 in 2nd for a lesser 2184 in 3rd. And downshifting from 3rd to 2nd is often a crapshoot with an old shifter.A better solution for this instance would be 3.55s which would put you at 2594.
The engine doesn't care what the diff ratio is once the car is cruising. It only cares what the total reduction ratio is. IE, you could have a 4.10 diff and a 1.92- 2nd gear, or a 1.92 diff with a 4.10- 2nd gear, the reduction is the same 7.87. There are only two places the 4.10s can help you; getting of the line and trapping at an optimum mph at the track. With 440ftlbs available, I can't see getting off the line being a problem.And trapping well is not a concern. So..... If I was you, I'd gear it to be at an optimum rpm at the speed you are spending the most amount of time, where you want a good amount of torque multiplication.
For me, that was 3.55s and 2nd gear. with 295s on the back, 30 mph in 2nd is 2582. Like you I have a generous amount of torque there, being able to light them up, at will.
Your results may vary.