[rwhite65]

Ok, well my limiting factor has always been my heads. With what you just said your plans are, here is what I would do if "I" were you.
Since you want a 351w in the future, but still want the 289 to run strong right now: Obviously, tuning the carb is a priority.....and there are many on here much more qualified at giving advice on that then me.

Seems like getting a good set of aluminum heads now, would help you in a few ways. One, u will free up a little weight in the front, which is good for handling and track times also. And then ur heads would not be limiting u on ur times, but would be good for your future 351w. From what I have read, u should be able to buy aluminum heads for the 351 w, and use some special pieces they make to allow them to bolt to the 289. Special pieces are needed because the 351w head bolts are biger the the 302/289.

Sure you might not use the full potential of the heads now, but they should help considerablly. Plus, now u have one more component to go with the 351w in the future.
Ryan