If you are using an Edelbrock or Carter AFB and are experiencing a bog at low RPMs, try experimenting with the following metering rods:
| PN | Cruise/Power Size | Size Difference |
| 16-241 (Carter) | 0.0705 x 0.047 | 0.0230 |
| 16-690 (Carter) | 0.0745 x 0.047 | 0.0275 |
| #1459 | 0.075 x 0.047 | 0.0280 |
| #1450 | 0.070 x 0.042 | 0.0280 |
| #1455 | 0.073 x 0.042 | 0.0310 |
| #1419 | 0.075 x 0.042 | 0.0330 |
| #1449 | 0.070 x 0.037 | 0.0330 |
| #1454 | 0.073 x 0.037 | 0.0360 |
| #1458 | 0.075x 0.037 | 0.0380 |
To maintain your cruising fuel economy, make your rod changes with Edelbrock rods of the same size economy step. You can maintain a fuel mixture for a given rod step (economy or power) and change the fuel mixture of the other step by maintaining a constant flow area between the metering step and the jet.
The following links are to tables that relate the flow areas of the various combinations of metering rods and jets.
Let's use Edelbrock Performer Metering Rods and Jets for this example. If you are getting good fuel economy with MR#1459 and you are using Jet#1429, your cruising flow area is 359.4 square inches (to the –5 power). Jet#1429 and MR#1459 yield a power flow area of 627.7. If you find that your engine is a bit lean for full power, you can easily increase your flow area by 5.6% to 662.6 with no change in economy flow area by keeping Jet#1429 and changing to MR#1459.
However, if you find that your full power fuel mixture is a bit rich with MR#1459 and Jet#1429, you need to find a metering rod and jet combination that has about the same economy flow area but has a slightly smaller power flow area. In this case, you can try using MR#1453 with Jet#1427 which has a resulting cruising flow area of 358.4. Jet#1429 and MR#1459 yield a power flow area of 627.7. Using Jet#1428 with MR#1455, gives a power flow area of 580.8. In this case, you decreased your economy flow area by only 0.3% but you more significantly reduced your power flow area by 7.5%.
The only practical difference between the two tables is in the part numbers. The Carter table lists parts that were available in the now obsolete Carter Strip Kit. The Edelbrock Performer table lists parts that are currently available through Edelbrock. The metering rods, jets, and springs will interchange between carburetors, provided that the carbs using only the two-step rods are considered. The three-step rod carburetor is not offered by Edelbrock so don't try using their parts in one. Be sure of the type of carb you have before you buy the parts for it!