Peter - No offense taken, simply trying to answer your questions.
The electric choke can be useful for those living in very warm climates (needing very little choke), or those living further north with manual transmissions wishing to use A/M manifolds.
We get calls daily from those using electric chokes with older automatic transmissions that drive their vehicles in ambients of 65 degrees or less that have stall issues.
It is true that if you compare almost anything new to almost anything that needs attention that the new may function better.
However if you compare the new 600 CFM clone to the original Rochester WHICH ONE HAS RECONDITIONED, my guess as to the difference in performance would be:
Low end torque - Rochester +10~15 percent
Fuel economy, city driving - Rochester +25~40 percent
Fuel economy, highway - Rochester +10 percent
Hesitation from stop sign - Rochester - none
0-30 times - Rochester about 1 second quicker
I can think of no area of carburetion where the 600 CFM clone would be an improvement (or even as good) as a reconditioned original Rochester on a stock 283 engine, except possibly in initial convenience. If you really MUST do the clone thingy, then the 500 CFM clone would be MUCH less of a disadvantage, but all advantages other than initial convenience would still be the Rochester.
If you are capable of doing the necessary modifications (adapter, fuel line, linkage, air cleaner) to adapt the clone, you are also capable of rebuilding the original Rochester.
Obviously, the decision is entirely yours. Just wanted you to be aware of both pluses and minuses.
Jon.
