David,
Having reinstalled my engine recently I can offer some suggestions which may assist.
I rebuilt the entire engine including manifolds, head, power steering, gearbox etc as a unit before install so the engine was ready to run once the fuel lines, water pipes and other linkages were complete. This makes assembly much easier than doing these things once in the engine bay. I think the only thing I left off was the fan.
As Dan says you can use straps but I routed them under the belly of the engine, one loop at rear and one at the front as you can't very easily use the engine mounts with the manifolds on. If you are using an engine crane, make sure the front of the engine doesn't touch the boom and hydraulic ram when at a steep angle. A crane with an adjustable boom is easiest (I had this problem).
Some items also worth reattaching with engine out to make life easier but ones you might not necessarily think about are:
Speedo cable to gearbox
Bolt through the engine mount under the manifold.
Air pipe from manifold to FI pump which runs around the back of the engine (if you have one mines a 230sl)
On rhd cars you also worth doing the solid throttle control linkages under the exhaust manifold, and double check powersteering lines/joints which are a pig to fix if they leak once engines installed as again they are under the manifold.
The engine is very heavy, so I wouldn't use the headholts myself.
I also retorqued the headbolts after only 100 miles which were quite loose, rather than waiting for 600 miles to pass. I repeated this at 600 miles and they didn't really need any further tightening.
Rocket
230SL 1965