Your 88 is a hydraulic roller motor... why would you downgrade to a flat tappet cam?
I'm not sure if this will work for you, but these are some kits that were recommended to me (
http://www.summitracing.com/compare.aspx). If I don't use one of those, I'll just buy everything separately and use an LT1 or LT4 cam... those are cheap and they are a major upgrade. I don't know if things changed for the 305 in 88 as apposed to the 87 cars, but from what I've been told and found, our cams a absolute junk! Here's the specs...
Duration @ 0.050 Lift: 179int/194exh
Valve Lift w/ stock 1.5 rockers: 0.350"int/0.384"exh
Based on that, pretty much anything is an upgrade! Since our motors are pretty much the exact same, you can check out the thread I started. There is some good tech in there and a few people talking about their experience with some cams. Well,
here it is (Stock cam & different rockers for more lift?).
Mike