Rear end problems

[Racefan]

That got some attention, huh?! But really, the conversion I talked about in my other tech post (427/TH400 in a 327/PG car) has a 10-bolt open mono-leaf with PG gears in it. Due to lack of ability to find one in my area (and cost factors), I am thinking of changing the existing rear to a posi unit with 3:73 gears and multi-leafs. Any suggestions on brands or any other issues that may arise in this? Thinking of doing this as a temporary fix until I can get the rest of the car done, then looking for a 12 bolt later. Is this more money/hassle than I think, or does someone have a 12 bolt posi unit close to Iowa that I could buy and come get? Thoughts?