Jon.
Thanks for that pointer on the application of the 420S. With 1939-40 jetting it didn't work well on my '36. Trying various main jet and metering rod combinations, keeping detailed notes on the effective jet open areas at the rods' large and small diameters and keeping detailed notes on performance brought me to a 94 main jet and a 1-step lean 1937 Chevy metering rod. With that combination the 207 cid engine ran well but had a very slight surge at barely cracked throttle openings. Going slightly richer to a standard 1937 Chevy metering rod yielded a "just right" seat of the pants feel accelerating, cruising at a steady speed and climbing some of the steep hills around here. I wonder what Joe's air-fuel ratio instrument would show?
If you really want rods, they come up on ebay fairly regularly;
Yeah, a guy with the handel "Ice racer" has them but he's selling those carburetor parts in fairly large lots, not individually. I'm a geologist, not a professional carburetor rebuilder like you. What would I do with 10 or 20 of the same jet, metering rod or check valve?
and I am told the grumpy old hillbilly in Missouri can custom cut them to any specification.
Missouri? Would that be you?
