The Quad 4 H.O's first came out in 1989 I think. I don't recall any 88's having them and I own 2 Grand Am SE's, a 1989 and a 1990. They both have the H.O.'s. I don't remember all of the specs, but factory they came with 180 HP and I think 165 or 170 lbs of torque. Compression is 10:1. In other words, they fly!!
I think after 1991 they started killing the HP because of startup emissions, head gaskets going bad, etc... although my 90 model now has 247,000 miles on it so far. But the original owner had the gasket replaced years ago as a recall. I have a 1989 HO I just bought from back home (VA) that I am bringing to CA over Xmas. It only has 82,000 miles believe it or not.
I like my Quads, they have been good to me so far. But I don't want a newer one...not fast enough. I still find myself racing....and beating rice burners with my 247,000 miles. I need to stop that stuff too.