You might try Classic Performance Products. I bought mine for my 56 through their eBay store. It was still a bit more pricey than I wanted.

http://www.classicperform.com/Store/1947_59_Trucks/4754AGTS.htm


Paul
1956 Chevy Task Force Webshots
My wife puts knots on my head faster than I can rub 'em. That's why I ask knot-headed questions.