Nah the chevette motor is completely different. Its actually from a viva - imagine how slow those were. Plus its actually a third generation, the first was only 1057cc, the second 1159cc and the final 1256! Its hard to imagine any engines slower than the 1256 ay.
The 1600 from the gemi is part of the g series family which is used in the bellets, 117s, gemis, piazzas and rodeos (maybe some others) varying from 1.6,1.8,2.0 and 2.6 from memory.
I think the gearbox xmember and driveshaft are different, but as far as the engine isself goes, they will all bolt into a chevette if you use gemini mounts (and chop the front out of you engine bay )
And yea gemi gearboxes are whack the selector is long as and comes from right up near the firewall. Gangletron.