yeah the 1.7 will add some lift but after u convert to mass air and want a diff cam bigger the 510 lift(maybe a lil higher) i would just go ahead and get aftermarket 1.6's instead of buy 2 sets of rockers
I am pretty sure they are 1.6. In any event, there are production variances from rocker to rocker, so the odds are that none of your stock rockers are exactly 1.6.
So even upgrading to aftermarket 1.6 roller rockers are an improvement over stock.