I know that some housings will not take a carrier with with the larger ring gears. For example; You can't put a carrier with a 4.11 into a housing that was built for a 2.70 gear. That's where the code will help. If you find the axle code(on the axle tube) you will know what range of gear ratios you can use. The only other way is to try the carrier with the ring gear in the housing and see if it fits. If it fits then you can set up your pinion.
Jim