Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: GSP7 on January 17, 2026, 08:42:07 PM

Title: Opinions on these "custom-50m-metering-rods"
Post by: GSP7 on January 17, 2026, 08:42:07 PM

'79 and later with.036 tip... My carb is 17080213

https://cliffshighperformance.com/product/custom-50m-metering-rods

Compared to the standard original 50m(etc) primary rod with .036 tip. with the dual taper/step

Im wondering, all things being equal, if these "custom" straight taper primary rods would need a larger jet to  run the same as the original dual taper with same size jet. Especially at off idle tip in.

Im wondering if I remove my Custom 50m rods and install my original dual taper 50m it would be richer off idle acceleration , all things being equal


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Title: Re: Opinions on these "custom-50m-metering-rods"
Post by: novadude on January 19, 2026, 05:27:32 AM

I thought all OEM "M" rods had a smooth taper to the tip and no "step" like K rods, etc?

Title: Re: Opinions on these "custom-50m-metering-rods"
Post by: GSP7 on January 19, 2026, 09:20:43 AM

No step, but the original rods had a "dual" taper near the tip.

Title: Re: Opinions on these "custom-50m-metering-rods"
Post by: Kenth on January 19, 2026, 11:35:24 AM

M4 rods w/suffix J are equivalent of early no-letter rods.
M4 rods w/suffix K are single taper and step to .026".
M4 rods w/suffix L are equivalent of 4M "B" rods.
M4 rods w/suffix M are single taper and step to .036".
M4 rods w/suffix P are single taper (steeper than K rods) and step to .026".
M4 rods w/suffix S are smooth single taper to .036".