acres90

hello everybody, i bought a '99 c5 a couple years ago, and the previous owner did some mods (headers, cold air intake ect, that i know of). it has the 6 speed trans, how can i tell if it has the stock rears in it?

65GGvert

Drive 75 mph in 4th gear, look at the rpm's. If they are around 3400 rpms, you have the stock rear of 3:42. Whatever your rpm is, divide by 1000 and you'll get your ratio. Make sure you're in 4th gear.