Im still a bit rich in the primarys, hard to belive on a 355 with a 600cfm carb huh? The smallest jet size in the track pack is #64 and stock jets on this carb are #65 will that do mutch? I need to run down and get some gaskets in a little bit so please respond quick!

Thanks!

 

Keep leaning the carb out 2 jet sizes at a time till
it looses drivability when cruising (lean stumble)
then go back up two or three sizes and try that.
This will not lean out the idle or low cruise, just the
cruise above 20/25 mph.
If you really want to lean out the idle curcuit, as opossed to the primary circuit, you'll need to
put small v shaped pieces of wire (.010/.025") in the idle feed restrictions in the metering block. Be sure there are no internal fuel leaks
before you start (leaky powervalve. leaky metering block gasket
etc) check if the idle air bleeds are open but do not enlarge
them. Compressed air works good for this.

 

A too-small carb will run rich cruising, every time; the too-large-for-the-carb motor will create more air flow under any given circumstances than the carb is designed for, so the carb will see a larger "signal" at the venturis, and so will feed too much gas for the motor's actual load, because it will look to the carb as if the motor is under more load than it actually is.

A change of one jet size in a Holley is usually imperceptible. In fact, if you measure lots of sets of jets, you'll find that a set of 64son the high side of their tolerance (say, 64.4) is almost as large as a set of 65s on the small side (say, 64.6).

3 sizes is a "standard" step for calibration purposes; 4 sizes is large; 2 sizes is a fine adjustment.

Smear a very thin layer of grease on the gasket when you put it together, just be very careful not to let any of it get into the passages, and that way you won't destroy them taking it back apart. Especially, put some on the bowl screw washer gaskets.

 

Thanks guys! I'll try the speed shop in the morning to see If I can get some jets smaller than #64. The engine has a little rich problem off idle nothing major but since I had a little time I figured I'd clean it up.


SSC

 

they hav closer tolerances.