Installing small block from the bottom

I have. I JUST did this on my '79 Magnum 2 days ago.

IF you have an engine hoist, use it to pick the front of the car up. Then roll the engine in place and drop it down. It is about that simple. Though a friend would be of help in lining up the K frame. I was jumping back and forth since it was just me all alone.

I didn't have a engine hoist. I had my car up on jack stands. If your jack stand are not all the way up, there maybe a clearance issue. As luck would have it, I had to take my heads off which lowered the engine height enough to roll under the subframe easy. Otherwise, it would not have clears with the heads on.
(The jackstands were also not at full height.)

Once you blot in the K frame, move right to the trans mount. Once that's in, install the front end and let her rest on her own feet.