Can i put a 1967 or 1968 grill, lights etc on a 1969 firebird?

NO, the front fenders are different and so are the front bumpers. It'ld probably fit because the front subframes and radiator supports are the same if you were to use the whole front "beak" which includes the 67/68 style front bumper and grille and headlights but it wouldn't line up that good with the 69 front fenders and the lower valance panel wouldn't fit the 69 fenders which holds the front corner lights. You would probably have to use the front fenders and inner wheel wells from a 67 or 68 in order to make it all fit but the body lines are also different at the doors. Alot of the parts are interchangable between the 3 years like the hoods and trunks and floors and rear wheelwells and seats and gl and rugs and door handles. I have alot of pics of my 69 Firebird front end apart on www.flickr.com.