there is no reason to "want only info on the 88 up engines" this stuff is basically the same on those trucks. My method? Ratcheting wrench or REALLY REALLY long extensions and an impact. I've used both methods.
I can't remember, does the trans crossmember sit inside the frame rails or below them? If it is below, consider unbolting it from the frame, put a jack under it first of course. Then lower the jack down. You should be able to see up to the top bolts. With the aid of aforementioned REALLY long extensions and a 3/8" impact you should be able to wing them out with little issue. Remove the distributor first or else you will smash it against the firewall.
If the crossmember is inside the framerails, unbolt it, jack UP as much as you can. Watch you aren't crunching anything underneath of course. Then use a ratcheting wrench and ratchet them off from under the hood. I've done it both ways, its no fun, but it gets done.
Option 3: Remove the engine and trans as an assembly. Remove the trans, bolt it to the new engine, throw them back in as an assembly. I think one of the other options will work better for you.
Option 4: If you have a lift, do a cab lift, haha.
I just did an engine job in a 2003 2500HD with an 8.1L. I used method #2. Ratcheting wrench on the upper 3 most bolts, and extension and impact on the other 4. You'd be amazed how similar some the newer stuff still is.