greenfire

I tried searching the forum before I asked this question, but couldn't find an answer. I plan on rebuilding my Ka24de(1998 Altima). For the kits, they break the years down as 1993-97, and 1998-00, but for the crankshaft and connecting rods, it doesn't matter. My question is what is the difference between the 1993-97 Ka24de and the 1998-00 KA24de? Are the ports in the intake and/ or exhaust a different shape? Are the piston rings a different thickness? ect. I've been searching for a rebuild kit for a couple weeks now and the 1993-97 seems to be about $300 dollars cheaper than the 1998-00. Sorry for the long post.