Putting a 850 engine back in the frame

I am in the process or rebuilding a '74 850 Commando. I am thinking ahead on how I will get this back in the frame. When I got the bike it was a basketcase, and the head was removed prior to pulling it out of the frame. I was hoping to completely build the engine on the bench and install it with the head attached.
Looks like a bit of a puzzel, with supporting the rear transmission cage and alligning the isolastics. I have the the manual but it is rather brief on explanation and diagrams. Is there a special process or sequence others have found to pulling this off ? The frame is freshly powder coated and would like to do this without screwing this up. I am using upgraded Mk III isolastics. It would be helpful to hear from those that have done this and find out how many people are needed and/or special tricks used.

It was a while back that I put the complete power train in a frame, but I might have done it by laying the engine on its primary, on towels, then maneuvering the bare frame, which weighs nothing, into position around the engine.

How much else have you re-assembled?

When I put mine together, I put the cradle and gearbox on first, then the fully built engine. But I did it without any wheels, so the frame was sitting on the floor. I found it really quite straight forward. Beginners luck maybe?!

I installed the bottom end into the frame and then built the engine up from there. I put the pistons with rings in the barrels on the bench leaving the pin areas exposed. With a couple of chunks of 2x4's for props lower this over the rods and put the pins in. Be sure and put the inside piston pin clips in before putting the pistons in the barrel. The head is a bit of a wiggle but not a big deal. The push rods need to be inserted up into the head as far as they will go. Wedge some shop towels between each pair on the head face to hold them and pull them out when you get the head centered. Getting the pushrods under the lifters is a bit of a pain. I use a pick with a 90 degree bend in it to manuever them. You still have to do them on the bench anyway.

I built up the entire engine on the bench and then put the engine in the cradle and put the bare frame around that.
Somewhere on this list is a pix of them doing this at the factory.
Only bother is you cannot be doing up the rest of the bicycle whilst the engine parts are held captive at the machine shop.

Just put my fully assembled Combat engine back in (rear breather in place). Cradle and gearbox were in situ, shockies attached to swingarm, coil assembly in place, front brake locked on, frame sitting stable on blocks, rear loop (both sides) tied off to rafters, block ready to support engine. Engine inserted from the right side and rear bolts fitted. Engine levered upward using hydraulic jack to insert front isolastic, bolts in and front and rear (vernier) isos set and locked. With frame suspended (no blocks) the engine sits on isolastics only so the rose joint head steady is attached, adjusted and spring set. Viola!
Note: front iso was difficult to manouvre as I have a low slung oil cooler - may be easier before rear engine bolts are fitted.
Ta.

Guys, Thanks really appreciate learning from your experience. Have done several Triumph 650's and on these I had installed the lower engine in the frame and built it up from there. This is my first Norton 850, and think I will build the engine on the bench and install it complete. Thanks again.