K20 1978 lift questions?

[K20Chevrolet]

Hey guys im here to ask about lifting my truck. I know there are a few out there but just thought id ask. I have a 78 k20 that im currently been restoring and just thought to do the lifting while everything is off. I have over load springs in the back currently but i was trying to figure out how much I can lift it with out haveing to start changing things like my drive axle and all that other stuff... i was thinking either 32" tires or 33" with a 2" body and 2" suspension.....thoughts? Id almost be fine doing 33" with a 2" suspension.