Specialized Tool

I have a 1951 Chevy 5 - Window pick up and I'm doing a frame off resto. There are bolt heads that require a specialized tool to remove the bolts from the fenders and brackets that I have never seen. It requires a tool that inserts like an allen wrench would but is shaped more like a thick straight screw driver with up slopes on the ends. This is my first resto and I am a little ignorant on some of the terms. I checked with the local Chevy dealer and they were no help. Can someone tell me where I can get this tool?  

Jim, the bolts are called "clutch head".  They havent been used much since the 50's, except in chevy shortbeds.  They are still avaliable but hard to find.  I found a set through my Matco tool rep.  These younger guys probably never heard of them, so you will probably have to serch the catalogs.  They may also be avaliable through sombody like Classic parts etc.  I would suggest that while you are looking for a set of bits, soak the nuts good with penetrating oil.  If you are not careful they cam out real easy on the old rusty bolts.  

Thanks for the info. I will try the Matco rep. and see what we can find. Thanks for the advice on soaking. I want to do this right, my truck is special. My Uncle just gave it to me. Been trying to buy it for ten years, he just found out that he had a brain tumor that is inoperable and wanted me to have it. The truck has 420000 miles and I am the 3rd owner. All three owners are James and I knew the original owner. I think my tag will be special....JAMES 3. Thanks again for the info.....Jim