How much horsepower does a 98 Camaro z28 have stock?

Answer 1

the earliest camaro ls1's were 275 then as time past they were bumped up to 305. This was taken from the Wikipedia website.

The LS1 shares little other than similar displacement, external dimensions, and rod bearings, with the earlier small-block V8 engines. It is an all-aluminum 5.7 L (346 in³) pushrod engine and was rated between 305 - 350 hp (227 to 261 kW) and 335-365 ft·lbf (454-494 N·m) of torque in North America, depending on the application. In Australia, continuous modifications were made to the LS1 engine throughout its lifetime, reaching 382 hp (285 kW) in the HSV's YII series and a Callaway modified version, named C4B, was fitted to HSV GTS models producing 402 hp (300 kW). The version fitted to the Pontiac GTO featured a higher-lift camshaft to produce 350 hp (261 kW) and 365 ft·lbf (494 Nm) of torque. Beginning in 2001, the LS1 received the higher-flowing intake (from the LS6), and a smaller camshaft to keep power at the same level; this also allowed GM to remove the exhaust gas recirculation (EGR) system (Camaro/Firebird only; 97-00 Corvette LS1 never used an EGR system). The block is very similar to that of the higher-output LS6; beginning in 2002, some LS1 engines were actually built using the LS6 block instead. The LS1 was on the Ward's 10 Best Engines list for 1998, but even though the ls1 is both larger and of higher compression, than the 4.6L 32 Valve Cobra Engine, it does not make more power. The SVT engine is clearly more efficient and superior to GM's outdated pushrod LS1.