Holley question..Again

First I would like to thank the people who gave me input on my last thread.

I looked into the advice given and it all makes sense. The Holley 82751 which I am running it just prone to run rich as it is to be used for the track.

My family is at the Jersey Shore this week, and I would like to drive down and spend some time with them, (but I have to work a few more days). Anyway, I was going to drive my car down (approx 2hour high way drive) and there is no way I am going to do this with the carb I have as 4-5 mpg is just not happening.

Now I am running a little more than stock engine as you can see from my last post, but do you think it would be worth it to take the 750 DBL Pumper off and just got to the local auto store and pick up a Holley 600 vac sec or an edelbrock carb to use for street driving? The Holley is like $279, which isn't bad, but I don't want to spend the money if it isn't gonna do much good.

Any opinions here? (My last post was "any holley experts here" so my engine specs are listed . Any more feedback would be helpful. One person mentioned an older 750 w/ vac sec, which makes sense, but would the 600 be even better for highway driving?

i run the 600 on most every street car with a mild sbc. most with od and get 20 mpg .