Well, my mechanic and I both learned something last week when he was working on my ‘70 W-31: there are no metering rods in the carb. What is the reason for this? Does any other Oldsmobile not have metering rods?

 

Both the W-31 and W-30 4 speed cars from 1970 didn't use primarily metering rods. The cars were factory tune this way and expected to be race from the get go.

 

The factory cam in both the 1970 W31 and the 1970 W30 manual trans motors didn't generate enough vacuum to reliably operate the power piston that controls the primary metering rods (though interestingly Olds did use them on the 1968-69 cars with the same cams). To make up for deleting the rods, the primary jets were reduced from 0.075" (W30) and 0.074" (W31) used on the 1969 cars to 0.058" (W30) and 0.057" (W31) for 1970.