it'll start but it will run like crap. Rock and a lot of other companies make a timing set with two marks on the chain that perfectly line up with the marks on the sprockets. the mark on the cam sprocket kind of kicked to the left a little bit from what ive seen on a couple chains and could easily be confused to set the timing off by one tooth. try bringing #1 to TDC and setting the rotor to the #1 plug with the adjustment in the middle. you may have to turn the crank a little to achieve the position.