What size tires are you running? That makes all the difference in the world. If you're running 225's then 4:88s are too low and 5.29s are out of the question, even for towing. I had 4:88s on my old 81, (where stock was 3.90 with 31's before I switched to 33's and the 4.88s were pretty low. Didn't like it, I was always shifting. Once I switched to 33's it was perfect.
You need to figure out what tire size you want to end up with then maybe go with a little lower gear, really depends on how often you'll be towing. Try a header and 2 1/4" exhaust, helps alot. I'm currently on 35's with 4.10's, (for now), and I have plenty of power on the street. My engine is on the strong side but it has a header, exhaust, and 270 cam.
My point is there are alot of factors to consider before dropping alot of coin on gears.