I did not mean anything about you did not do research. I hope you did not take it the wrong way.
"The blocks are of the same family and are based off of the S series block design (3S and 5S). The 5S has increased deck height (taller block), and a .5 overbore. Those are the only major differences between the two, aside from reinforcement ribs and such. The internals are also different, the 3SG blocks having much stronger internals being a performance engine while the 5SFE has a longer crank (longer/bigger stroke). The stroke increase and the bore increase is what makes the 5S block a 2.2 liter as opposed to the 3S block which is 2.0. Now, because they are from the same family of blocks, the water passages and such are all cut the same way (or at least, very very similar). They line up more or less. Because the cuts in the block are the same, the cuts in the head are the same. Refer to NEVERSTOP's picture of the combustion chambers. Even though the two heads are completely different, they share similar cooling passages in the head because they share the same block family...
On a side note, Toyota did do a revision to the 5S block in the later models. I forget which exactly, but I think it happened in 97 or 98 or something like that. This was the last block revision for the 5SFE and these 5S blocks, as I'm told, do not line up to the older 3SG heads. The later model 3SG heads (3rd gen, BEAMS, possibly ST205) may line up to the last revision, meaning they may not line up to the older 5S blocks..."
Link:
http://www.6gc.net/forums/lofiversion/index.php/t16388.html