If you are not embellishing on your power #s you should remove the tinker toy piece for something more substantial for the long term. 10 bolt means almost nothing but how many bolts hold the ring gear on the carrier. It could be a GM 8.5" gear set like the grand national and older pickups used to use or it could be a trans plant and has a 7.5/8" ring and pinion. the low power chevelles used a variation of this set up 8.2" as well. you will need to remove the cover which by bolt pattern alone will tell you most of what you need to know. your parts store usually has a picture of the gasket surface for each which is an easy way to tell if it is 8.5 of 7.625 job. the 8.5 I have used with some luck with 500 HP on it but requires frequent checking to be sure you don't destroy it. Your axles will be toy 28 spline if you have 7.625 car. some Tahoes used 30 spline but both are stock wimpy pieces so spooling should not be concidered ever. I hope this helps you get started.