Why cause potential valve train strain with a higher ratio rocker when you can get the same effect from the right cam?
Stick with 1.6s and get a higher lift cam.
What will the power difference be? I don't recall how .1 lift equates to exactly how much more lift, but compare it to basically just having a bit more lift on your cam, and that's how much more you'll make. Basically unless you get 1.7s super super cheap and can't afford a new cam, IMO they're a waste of time. UNLESS you're really old school and just doing a super low dollar build, and then you can get 1.7 stamped steel rockers off of a 460 and get a little more out of a stock cam.
it all depends on your cam grind and your flow chart for your heads. some heads flow no better at 550 lift than at 500. stick with what your cam grinder/manufacturer recommends.
I agree with ya'll !! IF you have the 1.7 rockers and a small lift cam, and want to raise the lift on your cam... then install the 1.7. IF you are GOING to buy the 1.7's cause "everyone uses them", then I say NO!! Cost is an issue... 250-325 for a set of 1.7s and gain 10 HP on the cam, vs 200.00 for a Camshaft that will give 35-40 HP!! See where I am going... dont Bandied the valve train!! On the tests run in a few mags.. the HP increase wa less than 10 HP!!!