The L98 has a lot of torque, but struggles to breath at the top end. So is there a conventional way (besides replacing the motor) to solve this problem?
The solution to the problem is an aftermarket intake manifold.
I've a friend who did all the standard hop ups (cam, heads,exhaust, headers, fuel pressure regulator,etc.) on his L-98 but it still falls on it's face at 5200 rpm. After long hours of research,which could have been greatly truncated with one call to TPIS or Lingenfelter, the answer was the Accel SuperRam. This manifold is similar in design to the LT1-LT4's from GM and will open your car up for some real top end fun.
If it is a horsepower kit you're looking for, something engineered to make your build up easier, call or go online with either TPIS or Lingenfelter. They can get you as much horsepower as your little heart desires or as the budget can bear.
I did the research and built my LT1 based on the TPIS 405HP kit and have been extremly happy with the results. I have had no problem dispatching the sub-compact "competition" in my area.
Cobra's with superchargers and Vipers are another story but as with any project, I'm far form complete.
I'll go through my notes and make a nice LT1 build up list in the next couple of days.
Steve