The Arntz serial number was stamped on the frame on the outside of the rail just in front of the left front wheel. My frame was number 6 but it is really hard to find since I painted the frame. You have the same setup I have and it is suprisingly quick. My friend here at work just built up a $6,000 LT4 engine for his C4 Corvette. during a recent "test", I pulled him about two car lengths in a quarter mile.
Life is good!
Paul