Doc, Unless you are looking for that last little bit of HP running the 1.6 are not going to benefit you that much (almost unnoticeable). Build your heads with the 1.5 rockers making sure everything it set up correctly & run with it. We tried 1.6 rockers on my 416 stroker but the possibility of valve to piston clearance was WAY too close. I went back to 1.5 rockers & have no problems twisting the engine to 6400-6700 RPMs through the traps. Just keep in mind, my application is race only.
