I put 4.10's in my Caprice, and it was just fine. The speedo reading was way off... which tended to get me in trouble, since I would under estimate how fast I was actually going. I didn't have any WOT shift issues, but the PCM was already tuned by Herter for the bigger cam, ect.
There have been a few guys who bounced off the rev limiter with a stock tune, and 3.73's / 4.10's.
Personally, I feel you have better tuner choices than Herter. But that's just me. No, I'm not attempted to open a debate, or drag his name through the mud.