The stock Z28 350 has 240 horsepower...the upgraded HO 305 had like 205 horsepower, both i believe came in the Z28, not the RS, the RS had the 170hp 305. The newer LT1 Camaros ('93 and newer ones - new rounded body style with the 350ci engine have 275 horsepower). He's totally talking out of his @ss. Just go along with it, race him and beat him and say, "wow, that's a REALLY slow car for having 280 horsepower". this link has specs for camaros:
http://www.f-body.org/tech/tech.htm#ThirdGen Is his the 80's blocky style camaro (3rd generation) or the newer body style? A '92 is the older style a '93 does have 280 or so horsepower, but with a 350. Race him and see how it comes out, don't worry about what he says, because he's blowing hot air out his @ss if it's a '92 RS. GOod luck