Just my 2cents worth but I have never used anything other than the Kent-Moore "funnel tunnel" for compressing rings on Detroits. And, I don't think that I would want to use anything else.
BUT...THEN AGAIN....
I worked in a big diesel shop that supplied the expensive special tools that were needed.
AND, I know of many mechanics....especially off road construction mechanics...that have probably "fudged" getting by without all the goodies and still kept the beasts running.
I remember marveling at a coworker dropping the pan on a 6-71 in the desert with the wind blowing about 25 mph and dirt swirling in the air and rolling in a new set of main bearings!!
That machine was still moving earth at 30 yards a load the last time I saw it so, I would say anything is possible if you have the shop manual, a precision straight edge, good measuring tools and an above average imagination.
But I'm also happy to say that I'm long time retired and don't have to prove it! ;>)
Good luck Ric243.
Jimmy D.