[nickthebandit]

Stromberg 81, 48, and 97 carburetor fuel inlet threads are 7/16- 28, a non-standard thread size. the taps are available from Wholesale Tool company for $ 7.89, plus $ 5.86 postage. I just bought one last week. Standard 7/16 thread sizes are 7/16-14, coarse thread, and 7/16-20 fine thread.