lowering your gear ratios overall will raise the revs!
you want a higher gear on the front sprocket ie 12 up to 13 teeth
or
lower on the rear ie 33 to 32 teeth
that will lower the engine revs for cruising
A taller front sprocket is better as the chain will have a longer circumference to go round and have an easier life.
1 tooth on the front also = about 3 teeth on the rear.