pontiacjack,
Sorry if I offended, my comments were directed at gear vendors making claims without any scientific merit, not at your question.
The short answer to your question is no, at least for very limited life drag racing gear sets.
Your question regarding torque capacity versus case hardness is somewhat ambiguous though. To give a definitve (or "straight") answer you would need to pose a very specific question, since there are numerous variable that determine gear performance.
Gears fail in basically three ways: scuffing, bending or pitting. Scuffing is more of a lubrication and geometry related issue, so case hardness is not of relative importance.
Pitting is a surface fatigue issue, so case hardness does have some importance. But a drag racing gear set does not see enough load cycles (a few thousand maybe?) to fail the gear in surface fatigue.
Tooth bending may be a concern if the loads are very high, but the highest stresses in bending will occur at the root fillet area, not on the flank of the gear. To maximize the bending strength of a carburized gear, this area is usually left unground, with the full case intact. But minor variations in case hardness at the fillet will have very little effect on allowable tooth bending loads. More important to tooth bending strength is the operating "pressure angle". In general, higher pressure angle will produce a stronger tooth.
If you will look at the reference noted in my previous post, you will see that a high quality, vacuum melt 9310 steel alloy, carburized, quenched and tempered at 300degF will have a case hardness of Rc 60 to 62, and a core strength of 187ksi UTS with elongation approaching 16%. These are very impressive numbers and are the reason 9310 is the gold standard for carburized gears. You'll note that Strange uses a lower grade carburizing steel alloy (8620) for their street gears.
These "as heat treated" numbers for 9310 are only half of the story though. The carburized case does not have a uniform hardness through it's thickness. It gets "softer" the deeper you go. And all of the quenching the gear goes through during heat treatment produces distortion. These distortions must be eliminated by a finish grinding process. Since the effective carburized case is only about .060 inch to start with, finish grinding can remove a substantial portion of it. In fact, the remmaining case may not be anywhere close to original Rc60 hardness level after grinding. With high quality aerospace gears, it is a requirement that a maximum of about only .008 inch of material is allowed to be removed during finish grinding to clean up the gear surface. If it requires more, the gear is scrapped. I don't think Strange adheres to such a rigid standard, since they are a commercial endeavor. So I would expect that a commercial grade gear produced in low quantities(like a Strange R&P) would have a relatively wide range of case properties from tooth to tooth and gear to gear.
As for the loads a gear tooth experiences, I don't know if "shock" is a good description to use. Any gear in the drive line of a recip piston engine powered vehicle (especially one with a slipping clutch and spinning wheels) sees an instantaneous torque of varying magnitude. Under normal conditions, the gear teeth should never experience a "shock" or impact load, since there is always at least one set or more of gear teeth in contact. This gear characteristic is referred to as "contact ratio". In fact, a high contact ratio is the main reason for using a hypoid type gear geometry. Unfortunately, increasing the pressure angle, as noted above to increase the tooth bending strength, reduces the contact ratio. So a balance must be struck.
Sorry for the long answer, but I hope you will gain something from my explanation of carburized gears. If I can explain something further, please let me know. I promise to try and not be so obnoxious.
