L5P Coolant drain and fill

[dmax_ty]

I’ll get right into it. Looking to do a drain and fill on my 19. Mr James kindly enlightened me to the fact that the 17-19 L5Ps coolant capacity is 31.5 quarts -- quite a bit more than the 01-07 trucks that I have worked with in the past.
Question is, after watching a few videos, seems all that you can get out of a drain and fill is about 20 quarts so is there a block drain or something to get more of it drained out?

I’ve got a tool to pull vacuum and refill but I’m curious if I shouldn’t do a couple of drain and fills?

 

[Ron Nielson]

I don't have a picture but there should be block drains on the block which look like bolts where nothing is attached. They are on the sides of the block below the exhaust near the bottom of the casting.

 

[juddski88]

The oil cooler housing is about as low and back as it gets. If you really are concerned about draining all of it, I'd drain from there.

 

[dmax_ty]

Got you. Not really concerned per se, but was curious as to if there was another/better way.

 

[Chevy1925]

We usually just evac with a bg evacuator. Pop it into the resi, undo the steam vent coming out the top of the resi and hold your thumb on the open port of the resi. Leave the steam port open. Gets you about 85-90% of the coolant out

The block drains are a bitch to get to. I’ve not looked at the l5p but you couldn’t get the pass side rear coolant port on a lbz easily but I could get the driver front one.