1.6 RR's
 

I might have a line on a good deal on some 1.6 RR's, just wanted to confirm there are no clearance issues with 1.6's? Has anyone ever tried 1.7's? What kind of gains can you expect from just the 1.6's?

depends what brand they are. some clear no problem. other brands you just have to cut some of the inside valve cover webbing off which is no big deal.

Or you could use a slightly taller valve cover, like the corvette ones.

no issues w/ 1.6 lt4s with stock valve covers here...
1.7s, 7/16 studs,isky plates,chromoly pushrods AND VALVESPRINGS!!!
not lt4 springs either!
you should be golden..............

You won't get major gains from just the roller rockers, I'd guess 5hp.