Steve,

Those aren't disappointing numbers for a motor that needs more tuning. With that cam, HP peak should be around 6000 rpm, and yours is falling off before 5000. Get that portion of the tuning corrected, and you'll have gained considerably more than 6 HP over stock.

But what makes a car accelerate is torque over a wide powerband (HP has nothing to do with it), and that can be quantified by the area under the torque curve on the dyno chart. Seems to me you've gained about 10 lb/ft with no reduction in the stock powerband -- that adds up to a heckuva lot more area under the curve, and that may also improve with more tuning.

The A/F leaning at high rpm is probably not a fuel pump problem so much as the D-jet not tracking the engine's needs correctly... I think you'll find considerable gains in both torque and HP will be found with the Megasquirt. I'm eager to see how that works out for you.