There be bad advice here...

 

What he said. Much easier and more effective than cracking open the cyl head vents. The block will have a reasonably full load of coolant when you crank it using this method.

 

From previous advice from here I drilled three 1/8" holes in the edge flange of the thermostat and it made all the difference on my last dry fill.

 

Thanks everyone. I filled it from the top radiator hose, bled the steam vents.
I ran it for the first time today. fired quickly and ran well with crisp throtlle respone in spite of open headers.

I was searching and found this link from Darkman,


http://www.pirate4x4.com/tech/billav...CoolingSystems

being an LS newbie this is one of the best explanations of the LS cooling system I've seen.