1997 Chevy Silverado 1500 air bag size?

I have a 1997 Chevy truck that im gonna bag. My question is what is the biggest size that i can put on front with stock spindles, im planning on buying Slam Bags (can i put 8" up in front?the wheel size are stock but im planning on putting 22" later on

dont really need more than the 7". it should lock up the front suspension. check out my profile for pics of my lift on 22's

I had 8s on mine...no problems...