I was looking at buying a header to put on my 96 Tracker with 1.6 16v. Is it worth the money? Does it make that big of a difference?

If installed with a aftermarket exhaust, I'd say you will still see minimal performance. More of a Sound or Tone to "hear" it running.

I think the appeal of the header is the look and it is something guys just like to do, enhance their vehicles.

However, I do think the header is nice, considering the OEM exhaust manifold is prone to cracking.

If you have a UN-Cracked manifold, don't worry about the mod.

Once your manifold cracks just buy a header.  If the manifold is ok then there is no point I agree.  I HAD to replace my manifold for inspection due to cracking so thats the only reason i picked up a cheap header.