I replaced the cast iron manifolds on my '97 with the later model tubular manifolds. The stock '97 utilizes a belltype of manifold/headpipe that attaches with two bolts (similar to 426 Hemi manifolds), while the '98 headpipe is attached with a band clamp to the manifold. You are correct, you will have to use the '98 headpipe/cat assy, but it will bolt right in with no problem. :thumb:SupremeViper said:But.....remember you have to have the '98 flex portion to go with them. I have never tried it, but I am under the impression the shorties will not mount ( /images/graemlins/smile.gif I said mount) to pre-98 cars. Anyone know the details?