I can pull some threads if need bee - Just let me know , and trust me i talk from experience with the 1407/1411 paper weight about the off idle - And then if you fix that you still have a carb that doesnt perform PERIOD !!!


Some great quotes



Now, in regards to the 750 version, just SAY NO! The carb is a slug. It has the worst signal of anything we have ever tested/dynoed, and is just not an efficient or powerful carb. In plain words it is a . censored
The 500-600cfm versions are great, the 750cfm is unworthy of being on an engine.
Best Regards,

Sam - Pres/CEO
Century Performance Center, Inc.



383 Dyno in "Moparts Tech Archives"



All the aftermarket carbs tested ran fine with the stock calibration except one...the EDELBROCK 750, #1407. this one ran very poorly.....it didnt really do anything well. it was just flat out lean everywhere. idle, part throttle cruise, WOT...and it didnt like to take a load at all. when getting ready to start a pull and going to full power, the motor would fall right on its face, then try to recover....finally recover, and then you could start the pull.
i found this to be pretty interesting because i also had on hand a Carter AFB 750 manual choke version which ran perfectly fine everywhere.
decent throttle response, good part throttle cruise A/F ratios, decent idle A/F ratio with the mixture screws out only 2 turns, and the WOT A/F ratio was right where it should be, and it had a pretty flat fuel curve as well.
i was running short on time, so i just continued on my testing of other things. when i was done for the night i pulled apart the Ebrock carb to see if someone had recalibrated it. this is not a new carb, but was pulled from my friends 396 Chevy yesterday morning. he's been running on the street, and didnt really indicate there was any kinds of problems with it, but there was an indication that another friend of his may have changed some jets or something.
well....that was not the case. it had all the stock jets, rods, and springs, and had no dirt or debris inside. the calibration was just that far off from ALL the other aftermarket carbs.
IMO, the Ebrock carbs are set up for motors that are much milder than what most people are building. well, most people i know anyway
anyway....back to the trenches.....