gear ratio help!

curious to know who's running what. i recently upgraded my 7.25 to a 8.75 that has 3:55 ratio in it. I've run the car a few times and it howls like a banshee (not in a good way). The gear shop suggested running a 3:73 ratio for some more bite. Curious to know if anyone has run that gear ratio?

my driveline is a beefed up 318, lunati cam, modified swirl port heads intake etc etc. I'm running a 2500 stall converter as well. tire size is 245/60/15

any help would be great.