I'm working on a straight conversion in my chevy truck. But I need to adapt one of the tapers from a small ball joint to the larger ones. Does anyone have a 1.5" TPF taper they'd rent out for a day? I only need to adjust the one tapered hole.

Otherwise, can someone point me to a place I can buy one? I've searched on MSC and didn't find one.

Sorry, don't have one, but here's where you can buy one:

$70 on ebay. XKUT tie rod reamer 7.15* 1.5"/ft taper
http://stores.ebay.com/XKUT

considering how much a tapered reamer costs, and how very easy they are to dull or trash if not used properly....

I think you will have better luck buying one.