They are relatively light but still, 600+ lbs vs 400lbs is a big difference
WTF are you talking? We're not discussing Terminator longblocks.(which BTW Ford rates at 655 lbs) If I remember correctly GM Performance Parts claims their LS3 weighs 415 lbs were FR claims their Coyote motor weighs 444 lbs. That's a 29 lb difference, and I know your about to go on about fully dressed motors or whatever but both motors have to be dress and I doubt there is a huge difference between them.
The roll over comment was a joke...kinda. But I pulled more mod motor heads in my career than I care to remember. Dropping an LS cylinder head onto a block in a vehicle is easy, from any position. Dropping mod motor head, especially a 4v onto a block in car is akin to an IRON BBC/BBF head, and you need to be ready for it :lol1:. I've done more than a few Aviator and Marauder heads, and with the secondary timing stuff installed they were 70lbs each! An assembled LS1 head is 24lbs.
Edit: I haven't pulled the top end off of a new 5.0 yet. But with the VCT I doubt they're lighter
I must of been on some drugs or something.(and I don't use drugs) I picked up the heads off a 01 Cobra motor that came with a Teksid that had a spun bearing and was being torn down. They sure didn't feel like you were trying to lift a concrete bag or anything. That's been a while though so maybe I'm just forgetting, but I do remember thinking they were a lot lighter than I thought they would be. I sure don't think they weighed anything close to a iron BB head. Hell I didn't even think they weighed as much as a iron SB head. There is quite a noticeable weight difference between a iron head and an aluminum one and as I'm sure you know a BB topend is pretty damn big.