Yes, The engine will bolt right in go ahead an bolt the 5spd on the engine and torque it down before you install it. Leave the ZX engine alone intake and everything will go right in. Use your existing wiring and hook it all back up just like you unhook it from your 77 engine. You will have the head temp sensor on the passenger side of the head unhooked as the 77 computer doesn't use it. There are some vacumn line differnces, up by the thermostat there is a port on the ZX engine with several spouts use as many as you need and cap the rest off. Use the tranny mount that comes on your 77 on the 5spd as the ZX is a little different ( swept back - the 77 is straight). You might want to swap the 77 distributor onto the ZX engine though or you will have to fiqure out how to wire in the ZX model ( which you can find instructions for on this site ).
I did this exact project 78Z swapped in an 82 ZX engine & 5 spd, before I even knew about this forum in 1993. I had just bought the 78 and spun a bearing, well I was planning a 300 mile drive and needed a car. My friend sold me his wrecked 82 and I set out to do my first engine swap. 12 hours later I was driving my 78 up to see my girlfriend for X-mas runnin like a champ. I really couldn't believe how easy it was.
Matt