If the flywheel was partially removed by taking out the 8 screws or small bolts holding the flexplate to the hub, it's possible it was reassembled out of time.
To check - Remove the flywheel nut, rotate the motor until it's approximately at TDC and look at the crankshaft key position. At TDC the key points directly to the center of the distributor shaft. Reinstall the flexplate with the timing marks in line with an imaginary line from the key to the center of the distributor shaft.
Next take the timing pulley belt flange off and see if the arrow on the timing pulley points directly to the flywheel timing marks. If they aren't in line, remove the timing belt from the distributor, it slides up and off as the flywheel is rotated. Put the belt back on, again it slides down as the flywheel is rotated and you have to offset the timing pulley a tooth or two until the flywheel key/timing marks are in line with the arrow.
When the timing pulley arrow, flywheel timing marks and flywheel are all in alignment, button everything up and put the flywheel nut and timing pulley flange back on. At this point the motor is timed except for max timing advance, but this shouldn't be off unless some one has fiddled with the timing stop screw.
To make things a little easier when rotating the the flywheel/hub, take out the spark plugs
