while we r on this subject i always wanted to ask. Its known that ss are under rated with hp at the wheels now is this generally known for z28's 2? also most of the stock ls1's(or close to stock) i see putting down monster numbers are 2000+. Has anyone here seen ealier ls1's put better numbers than the stock figure. I have a 98 z28 a4 most people are telling me that 98 z28's have 285 at the wheel? i

 

That sounds about right. The 98's seem to be a tad less powerfull than the 99+ cars. Even some 99's have lower numbers than most 00+ cars. But your best bet is to put your car on a dyno and see what kind of power its actually making.

 

An SS won't make better dyno #s than a Z28 unless it was ordered with the less-restrictive SLP exhaust. Most dyno sheets I've seen of 98 automatics are in the 280-290 range. IMO, this is due to the exhaust manifolds and less than optimal ECU tuning.