I have an 1863 Indian-head cent that is substantially different than all the other Indian-heads that I have. It is MUCH much thicker (at least 50% thicker, by my eye) and a very different color, too (paler and tanner than the typical brown penny). Is that normal? Was that year just different with the war going on?
The composition changed for the 1864 cent. That's when it went to bronze (for a long time). For the flying eagle and early indians, it was a copper-nickel composition, which was .880 copper, .120 nickel. The weight was also 1.56 grams more pre-1864. And also, the color is a lot lighter.
That's right. Your IHC is a normal copper-nickel cent. Later IHCs are bronze. This info can be found in your Red Book.
