the rear end in my 87 has gotten quite sloppy lately and i decided to change the spider gears in hopes that it would clean up the slop. however after ordering new spiders and attempting to install them i realized the new ones are smaller and have less teeth. i measured the ring gear and it measures too 8.5 not 7.5\625 like it should however the housing looks like the factory 7.5 camaro housing and the axles are 26 spline like they should be

is i possible some one could jammed a 8.5 carrier in a 7.5 housing?

 

How many bolts are on the diff cover. You may have a Borg Warner 9 bolt. 9 bolt and 10 bolt parts are not interchangeable. They are 2 completely different diffs although they share the same mounting points to install in a third gen.

There's also a possibility that you have an aftermarket, over the counter, Dana 44. If the rear cover is smooth, it's a 10 bolt. If it has a rubber fill plug, it's a 9 bolt. If it has a metal fill plug then you have a rare Dana 44 which will have a 8.5" ring gear. It wasn't installed in the car from the factory but at the time, could be ordered directly from GM and replaced.

 

26 spline axles were only used in the 7.5/7.6 10 bolt rear end. You can NOT put 8.5 parts in the 7.5 rear end. There are at least 3 different sets of differential gears that were used in the 7.5/7.6 standard differentials. Your '87 will have the 7.6 rear end with the larger 26 spline differential gears. The gears that you got are for the older 7.5 rear end.

 

no its definitely a 10 bolt rear end

 

so the only answer is that i miss measured the ring gear...

 

Yes.

I've probably got several used sets of those gears.