Chevy van may have "jumped" time??

Hello all,
A question on the positioning of the timing chain and gears. When the marks are aligned (crank at 12 o'clock and the cam at 6 o'clock) should the rotor of the distributor be ready to fire the #1 bank? The rotor is facing 180 degrees opposite of #1 when the marks are lined up now. The van has a lot of miles on her (200k+) and I think it has "jumped" somehow. Will not run. Backfires through the intake. :confused:
2002 Chevrolet Express 3500
5.7 Vortec
4l80E

When marks are together as you described, you're set to fire on #6.

pull number 1 plug..stick you finger in plug hole...bump engine till you get compression. Look at marks on balancer and bring slowly to #1 TDC. Then look at rotor alignment