No requirement for 3.73 with BBP. It was available with any gearset. The 3.73 was a separate option and is on the door tag or on a tag on the rear end itself. If the car is used, you can verify by raising rear and spinning the tire through a revolution, marking the driveshaft with a paint pen and watching the driveshaft turn. Counting the number of DS revs for each tire 360 will tell you the ratio.
Track Pack cars for 13+ have 3.73 standard.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto N/A tune. 100 shot nitrous on BBR tune. Best e/t 11.38 at 120.85
2012 Premium GT, Candy Red, Brembo package, 3.73, MT82, Comfort, Tech, et al. Procal tune, Roush UCA, UMI poly LCA, GT500s, Steeda red bracket, Hoosier 28x10x16 bias drags. Best e/t 11.91 at 115.23 RIP