i seen these in dennis kirk. You put them in ur carbs and they spin the air to make a vortex, they say they improve mpg and eliminates standoff. Has anyone tryed these before? Are they for real or are they a joke?

Simple physics makes these things a JOKE.

Think about it...........

The more air that your engine can get, means more power (if tuned acordingly of course). So why would you put anything in your carb to take up space and limit how much air gets into the carb???????????????? Its simply a JOKE!
Air spirling can help, but not enough to offset the losses of the air restriction.

the theory makes sence. making you carb smaller increases velocity. velocity is good. might work if you think your carbs are too big. otherwise, as worthless as aftermarket reeds on a stocker.
IMO mike