If you have no engine stand, the first order of business is to buy one, and don't pinch pennies. Inline sixes, even modern ones, are long and top-heavy, and tend to tip over forward. If you think an engine stand is expensive, check out the hourly rate at your local emergency room. Get a stand with FOUR wheels, and one that's long enough for the front wheels to be ahead of the crankshaft pulley.

For instance :

www.ebay.com/itm/325620483773?

I like to acquire a couple of pieces of square tubing that will slide into the existing tubes, and extend the front wheels several inches further forward. Drill holes for lock pins, or weld nuts on top of the original legs for a locking bolt.

As well as being safer than manhandling the engine on the floor, you'll save yourself untold amounts of frustration and wasted time by being able to work standing up. Work smarter, not harder!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!