Casper, do you have the stock H233b rear end? If so, check out your rear brakes and insure that they're adjusted correctly. If they go out of adjustment (which I saw more out of adjustment than I saw adjusted corrctly!) your brake pedal will be lower.

I put in my 9" and had the same pedal as I did with my 'b', but after adjusting it all, right back to the top.

With the truck in neutral, rear axle in the air, turn the adjuster until you get the shoes to rub a little. The yank on the parking brake cable to re-center the shoes and adjust again. Keep this up until you get the shoes to rub (gently) on the drums after you apply the parking brakes and release them. After both sides, drive it. Pedal should be further up a ways and feel normal again.