Yeah I used a socket that fit inside the freeze plug.

I only did the rearmost one on each side of the block. I am having overheating issues and wanted to confirm the debris in the block and flush it out. Not as much as I thought, but enough to where it came out dark brown when flushed with the hose.

Installation went smooth, and slid right in. It took longer getting the starter down/out and removing that freeze plug, than it did putting it back in!

When I have more time, I'll be doing the other four, as I have to drop exhaust and remove motor mounts.

After the flush, the truck does run a little cooler. But not a lot. She climbs to 205*-210* on long steady inclines (over the course of 3-4 miles). But cools right off on flat ground. Idles at 195*-205* but cools down once moving.

Water is brown again after about 10 miles of driving so I still have debris in the block somewhere(?)