stock syclone heads (LB4's) are a totally different chamber design than the 96+ (vortec) heads. The 96+ heads have a kidney bean shaped fast burn chamber.
1993-1995 non syclone/typhoon heads (L35's) are a direct bolt on head for the syclone and owners have reported measurable increases in power after installing them.
I run 1996+ heads on my syclone with a stock intake. In order to pull that off, I had to redrill the vortec heads for my syclone lower intake bolt pattern. Also, I added material to the lower intake the machined the welds and port match in order to seal the taller vortec head intake ports. I'll see if I can dig up some pics of this.