If you want to save some money and do not want to check the center line - at least compare your old timing sets gears and marks to the new ones on the replacement set. At least you'll then have some idea if the marks are out of whack.

Once upon at time I had a name brand timing set that was mismarked. I installed it and low and behold the motor ran like crap. I pulled it apart and found one of the marks was a tooth off. Ever since then I check the centerline on every build I do. Better to know, than not know.