The 373s would be a waste if you can only burn rubber with one wheel. It does not make you accelerate any faster either. You just wear out one tire, then the differential has to work harder because of the different ODs of the tires...Think it out.
You're lowering your gearing. Applying more of your torque to that single rear wheel. If she'll spin that one leg now she'll roast it off with 3.73's. And even if she won't spin it now it's a good bet she will after wards.
So I guess the actual answer to your OP is no, it isn't worth it without doing the posi at the same time.
If you're going to take the time in removing the OEM gears, and then install new gears and go thru setting up the proper backlash with the new gears, that's a BIG waste of time in not installing a positraction carrier IMHO.
Save your money and buy an Eaton carrier from Dan @ CIA, and do it all at once.
It looks like I'll wait a while then, funds won't allow anything just yet.
Just bought some use Vette Y2K wheels, still need to purchase adapters/spacers and I'm adding two new 285/40-18's to the rear.
And at the cost of these tires, I won't be doing much roasting!