I feel your dismay, i'll give you the short version. I replaced a 454 on a 85HR and some of the same rules apply.
1.)Took the engine out the dog house thru the side door(would not do it this way again, engine to high very unsafe)don't know if this would even apply to your coach.
2.) Rebuilt the engine shoved it back thru the front grille/radiator area. What i did is got some 3/4 plate bolted it to the manifold(where carb. bolts on)with a eyelet and with a engine jack was able to put it thru the front, now if you still have a clearence problen leave your oil pan off till you get it into position and then install.
3.) This is the most important to me, irregardless how good your transmission seemed prior to this, replace your torque converter, its cheap insurance, believe me all my hard work was in vain because of this simple step i bypassed.
Overview:Would i do it again? NO. Was i glad i did it then? YES. Did i learn somthing? YES. What did i learn? Don't do it again.
My problem then was in 05, that i had a coach maybe worth 10,000 and they wanted 8,000 to do a turn key engine rplacement, i did it myself everthing brand new except Torque converter for 3,700 this was in 05. 3708
