The most likely occurance is that since we have a two piece dipstick tube, that the tube, when repositioned in the block, was not set quite right, and there for will give you the impropper reading. (That is very common, and easy to do... don't ask me how I know)
So what I do is change the oil and filter, fill hert up, let it settle for a while, and then check the level. (make a new mark if you need to) and then you know where it tops off at. Anywhere from 5 - 6 quarts will be ok, but the proper amount is obviously better!
How is the car doing by the way? If you have a chance, can you post a link to some pix of your car, and hood etc... I'm sure some of the guys here would like to see it! It's some nice work!