What are the overall effects of undercarbing an engine?
...
So Im thinking I can choke it down with a 500 Eddy for her use inittially then swap the 850 DP when I go to the track.
Just a guess here. If your wife were to drive it just cruising around on the street, and it were tuned properly, I think it would be more than fine. It would probably drive a whole lot better around town. But, if you were to go WOT, you'd have to have a big enough secondary jet to feed it enough fuel. The Edelbrock 500 CFM has the same size secondary venturis and secondary bore as a 750 CFM carb. So I'm guessing with the right jet in the secondaries, it may work out ok. It would be down on power due to the lack of air / fuel through the primaries (and thus through the whole carb), but I'm guessing you could tune it to safe AFR's and not be harming the engine.