Took my car to a dyno yesterday, and it verifies a very minor issue I notice. I would like to know the best way to lean the car out at the initial hit of WOT, but not affect the fuel curve afterwards. The car is rich at cruising (and I notice this with a slight hesitation while holding the gas pedal in one position, maybe 15% throttle), and goes very rich when you floor it...then the A/F comes up to a solid 13.0:1 and stays there after a second or two. Any tips on leaning out cruise and the initial hit but not leaning out WOT? It's a holley 750 DP.

The duno tuner should be able to tweak a few things out for you,then make a couple of pulls to see if the changes did anything.

What did the guy at the shop say?

what was the a/f ratio at idle. sounds like a power valve issue. its hitting to much maybe or coming in to soon. does the timing snap up quick enough for the fuel?/

The really rich part on the initial hit would be considered normal, as it's a function of the accelerator pumps. You could try playing with the pump stroke by changing the cams and/or trying different squirter sizes.

Rich at cruising is probably the power valve.

Bear in mind that you're trying to apply the computer world to a piece that predates computers by several decades, so you might not be able to fine tune it to the extent of an injected car.