First off, your NOT going to be able to run a loopy cam in the '98. Cuz, it will drive the EPROM crazy trying to adjust the timing. Unless you dis-connect the EPROM/computer and I'm not sure you can even do that on a '98 model.
Anyhoo, try giving Crane or Comp. cam a call and talk to them about it. I did this back when I was starting the overhaul on my 5.7L and they(Crane Cam) advise me to go w/ the Powermax. To get better lo end and mid range torque. Which I did and I'm very pleased w/ the Powermax cam from Crane.