4 speed guys, I have a question :

1/2 tons did use A833 overdrive units. Whether they used the bigger "truck" flywheel I do not know. They were a long tail gearbox like a B body
I took a 833 out of a B100 van once and it had the 11" flywheel. Wish I keep it. I do not see why the bell housing would not work, as long as it were installed as a set with the transmission (I believe you are referring to the one on the left. The one on the right is a 833). It might be a little tight but should be able to make it fit. I do not see why a 10.5 inch flywheel would not fit also as long as the transmission input was snug in the bellhousing.