I am rebuilding a 74 Nova posi rearend (8.5) for my 69 camaro. I have replaced the gears, clutches, & bearings. During my rebuild period, I have lost my spider gears. Are the spider gears in an open differental the same as a posi?

The answer is usually just a "Search" away ;)
No - they are different and the Posi gears are hard to find ...
link to past post with info - http://www.camaros.net/forums/showthread.php?t=159036&highlight=spider

That was my post above and thankfully I was able to find a set of used posi spider gears. Only place I could find 8.5 new ones are by Yukon gear. Kit includes posi side and spider gears for $302.00 (may as well buy a new eaton unit)

I have some open differental spider gears which are to tall. My brother is going to machine them down to the same height as posi ones. This should work because the only thing wrong is the posi S spring will not fit.

Good luck with that. I doubt that it will work. These gears are heat treated and very hard. He will have to use a carbide cutter to cut them. Be sure that the teeth make correct contact with each other or you will end up with a pile of gear teeth in the bottom of the housing. You would be much better off finding an old 2 series posi and getting the gears out of it, or find the ones that you lost.

I fixed it. I was trying to install an eaton 4 spring posi pack on a 8.5 rearend. The S-spring is not as wide. I now have open carrier small spider gears(2) with S-spring.