If you have a carrier for 3.73 and numberically lower, you can use a thick gearset. If you have the 3.92 and numerically higher carrier you would use the standard gearset.
i say a tiick gear is just as strong as a standard gear but some people say that you get more noise from a thick gear
i am running a 4.88 thick gear & have no noise ( gear noise is in the brand & how they are set up )
hope this helps