I don't recall completely but didn't the Cobras come with 305HP and the Z28's have 285HP. I don't remember the TQ numbers or weight of each though.
305HP for '96-98 Cobras, 320 for '99-01 (sans whatever intake manifold debacle Ford had going on at the time). Between 305 and 335HP on the '98-02 Camaro/Trans Am cars, depending on year and trim. For instance, late '01 and all '02 SS and WS6 cars made good power, but a stock '98 Z like mine would have made 305HP. Not a huge difference, but noticeable. Gearing was really the difference maker with these cars.
White Ram Air Formula best combo of any 4th gen. Would love to have one then and now.
No doubt the LS1 was faster especially MPH. But my 01 cobra in the summer of 02 went 13.3 @ 105 stock. And hurt the feelings of a lot of LS1 owners who thought they'd beat me no problem.
While that seems to be on the upper end of stock Cobra times if memory serves me right, plenty of LS1 cars were making those times. Either way, stock for stock and mod for mod, it would be hard to bet against an LS1 versus an NA Cobra.