Probably easiest to put the sierra head onto swift block due to distributor facing the wrong way.

Pulleys and water pump may need changing over, depends on belt type,
and wether you want to rum multi V belts or not.

If using the swift multi v belts, it makes it easier for power steering and Falcon Alternator jobs.
But you may need to make an adaption for Sierra fan,
or use a thermo

If you use the Sierra water pump and get a dihatsu charade water pump pully you can run your origanal fan but the pully will need to be spaced out with a washer to line up with the crank pully this way you can keep you origanal fan and runs a multi rib belt to suit a falcon altornator upgrade later

if ya gunna sell ya sierra dont do it!

ya will have go through all the crap of gettin the block restamped etc....sell the car as matching numbers car and give them the spare engine

In Queensland if your engine is cactus and you fit another (the same as you are pulling out)) you buy another engine, fit the engine to your car, drive it to a Qld Transport office, tell them you have fitted another engine, they come out and check the new number, they go back inside and make sure that number is not from a stolen vehicle or from a currently registered vehicle and they update the system with the new engine number.