no, you should be able to use your stock push rods. What's your stock rocker arm ratio: I believe it's 1.6:1. It's just like our V6's we can use 1.73:1 or 1.8: rockers and the same pushrods. The bigger ratio just gives you a little more lift.
1.5!?!? didn't know they're was such a demon, yeah, depending on brand you might or might not have to change pushrods, FRPP's uses the same as stock, and they are decent roller rockers, just get ready to do some grinding on the vavle covers, and it wouldn't hurt to check piston to valve clearence, nore check valve train geometry while your at it...
google (correct valve train geometry) get ready to have some fun
check your rocker geometry!! any changes will affect this including simply adding screw in studs ,guideplates, and 1.6 rockers.
check for proper clearance between rocker and retainer, rocker and base of screw in stud, and contact pattern on the valve face.
Dont resort on asking others to guess your setup- a simple valve job, or different head gasket can even mess things up.