Unless you're looking for "all-out everything you can get out of it" performance, I'd go with the 1.6's. IMHO in your situation the valvetrain strain/friction just isn't worth that extra little bit of lift you're gonna get. Valvetrain geometry is SOOO critical, and it's the biggest horsepower stealer in your engine. The extra .1" of lift (at the rocker tip) is probably going to steal more horsepower than it'll make for you. You'll have more reliability, and less chance of turning a pushrod into a pretzel. That, and you'll save yourself some beans by returning that stuff to summit.
Just my $.02!
