Carb # 17056262 '76 Pontiac 455 This carb may not be a virgin, the covers over the idle screws were missing.
1. Read in The Good Book that "all" secondary "jets" are .136 diameter. On this carb, I can drop a .140 drill bit into each hole and there's maybe a thousandth or two of clearance--but I don't have a .142 drill bit to verify.
The secondary metering rods (bigass L-E-A-N "DB" units) have some corrosion/pitting at the large diameter; I think that's where they "park" in the jet when the air valve is closed.
I'm wondering if the secondary jets are supposed to be that large, or if the jets have been "pounded out" or eroded to a larger size. Will photograph, host and post later today.
2. Primary metering rods are "45L" What does the L signify?
3. The choke pulloff takes 15 seconds to release. Holds vacuum, seems to work OK, but the release time could be measured by a glacier stick. I don't see how it's going to allow the secondaries to open in any reasonable fashion. Defective? Were ANY OEM pulloffs that slow to release? I know about drilling an orifice larger, but I can't find the orifice. Again, photos coming.