The SAT practice test was a collegeboard test on their website, and the ACT score was from an ARCO book, which I now know from forums to be significantly harder than the real ACT.
Even then, I wouldn't count my chickens. Some people do better on the real thing than on practice tests; some people do worse. Take the test, see how you do. (And take it before you're technically a 10th grader, when the cuts are higher, or be prepared to meet the higher cuts. ETA: looks like that would mean registering by tomorrow for the ACT, and by Tuesday for the SAT.)
About the academic explorations and intensive studies programs: what are the corresponding cutoffs of the programs.
IE cut for humanities / writing is 610 or 27 for 9th grade testers, and 660 or 29 for 10th grade testers. For math, 680 or 1240 for 9th and 730 or 1340 for 10th.
http://cty.jhu.edu/summer/docs/academic_princeton_eligibility.pdfAE cut for humanities / writing is 510 or 21 for 9th grade testers, and 560 or 24 for 10th grade testers. For math, 530 for 9th and 580 for 10th.
FWIW, my usual suspects for accounting for the score differences you see would either be, "you're someone who tends to do worse on the actual test than the practice test" (an unfortunate problem that does afflict some very smart kids), or "those tests have similar names, but don't actually assess similar skills" (which I believe, based on my own kid's NCLB and EXPLORE experiences, to be true).
