With all respect to those who have posted that have had success with the clones:
Comparing something new to something needing work will normally mean the something new works better.
However, comparing a clone on a SBC to a properly functioning Q-Jet would result in:
(A) fuel economy of about 10~15 percent less for the clone
(B) low RPM torque of maybe 5~10 percent less for the clone
(C) more difficult hot starts for the clone
(D) no improvement in high end HP for the clone
Remember that the Q-Jet is a 750 CFM carburetor (150P/variable 600S). The 600 clone is 250P/variable 375S (no, this is NOT a misprint!).
Running the clone through a square-bore -> spreadbore adapter (not changing the intake) reduces the clone to a 525 CFM (150P/variable 375S).
However, the clone is convenient, if you don't object to the loss in performance.
Jon.
