Mr. Chris Sobak,
Info for you more than anything else....at the time the Prudhomme Army Vega would have originally been campaigned, the blower most likely would have been an original GM 6-71 blower. There is an outside chance it could have been a GM 8-71. They were about the only blowers used by successful teams in the 60's and 70's. Littlefield blowers did not begin manufacturing blowers until about 1980.
As an aside, I actually worked as an engineer on the manufacturing line for the GM 6-71 and 8-71 blowers for a couple of years in the early 80's. The manufacturing tolerances on the rotors were incredibly small....much smaller than many people might think. Unfortunately, no free samples!!