http://www.cumminsforum.com
Conversion thread is at the bottom
http://www.4btswaps.com
Its called research. If you can't get what you need from those website and the search feature, you shouldn't be attempting this project
Based on my research on this topic over the past 2 years, i would suggest you slow down a little bit and cover all you basis here, rather then just trying to mig weld a cummins between two frame rail.
Vortecz brings up all the main points, like tranny and motor mounts.
What do you have for a donor or you just picking up the first 12v that you can find and hoping it runs when you try to start it up after the swap.\
Despite being an 3/4 ton 86, i don't see the springs hold up/lasting all the long, let alone sitting at the same height as they did with whats currently in there.
I would have to go back and look as its been some time, but you need to consider the steering pump. I know the fords have an issue and usually end up having to use the dodge pump which causes some hassle, the chevys i do not remember.
I am not really one to speak, but i can safety say that on those two forums (as well as others out there) i have read every swap forum possible. This isn't as easy as some people think who have a mig welder in there garage and some scrap steel kicking around, as a lot of people have that idea