Im thinking about putting some bigger sway bars on my 85 z28. right now it has 32mm front and 23mm rear. Im planning on getting used ones off another third gen, not new bars. So I definately want 24mm rear, but Im not sure about front. After doing some searching I see theres a 36mm hollow and I know theres a 34mm, but Im not sure if its hollow or solid or if both exist. Im assuming the 36mm hollow is preferred is that correct?
also, are the end links and bushing brackets the same for different sizes or will I need to get them too? the endlinks and brackets I have are in good shape so If I can use them I will. thanks

If you have the money and plan on playing around with the car's characteristics, get a 34, 36, and a few rear bars. That way, you can fine tune it.
If not, for street use, the 36/24 combo is generally well liked.

Yes they both exist and I have both of them I'd like to get rid of. You can tell the hollow ones by the bends. where the bar curves it is slightly flattened out where as a solid bar is consistant all the way through the curves of the bar. Also the hollow bars have a drail hole in them and where the link connects it has small lines where the bar was pinched together on the end. Solid bars just look like they were flatened with a hammer. You can use the end links you have ,but the bushing where it bolts to the frame is different(Obviously bigger or smaller for different bars) My bars come with the bushings if you are interested