On that particular car, I don't know, but for years Kurt has had an excellent working arrangement with Jim Dove. It's very likely that the heads are Jim's work.

KS

Highly unlikely that Dove had a head at that level. I do know that Paul Adams was a big fan of Blue Thunder heads although no idea what is currently on the car. That car sold for a steal of a deal and it's great to see it out running hard.

My setup is 1-1 and it's just using the factory style linkage. As mentioned, with some fooling around you can adjust the rods to achieve your desired result. As for any benefit, just seems to work better on a Drag car whereas on the street the progressive is likely easier to deal with.

I have had 2 sets of Dove Aluminum heads and the ones on my 427 had some porosity but never a problem. The current set on my 428 are horrible and why they don't leak something amazes me however they have been used and abused for a long time without issues. A bit lower price would make these more attractive but since I'm not a buyer my opinions don't matter.

I'm pretty sure all Dove heads are "SK" so that designation means nothing but one tip I have is to put your head gasket of choice on the head and make sure the oil transfer slot lines up with the hole in the gasket. One set I had the slot was too short and it starved oil to the rockers. Found that out the hard way.

I'm a Cougar fan as well but some yes and no from me on this car. Nicely done (not necessarily what I'd do) and $$ spent however it doesn't seem very fast despite the 750 HP claim. Owner does need to power shift as mentioned and it possibly  could use more Carb but if it made 750 with those, then why bother.  I've had the same 600's on everything from a 454" to my current 390 with no issues however I don't street drive. Bottom line (for me) is it's cool but not as impressive as the video makes it out to be.

You might even see lower coolant temps but the oil will certainly get hotter. What Brent said about an Oil Cooler and even an oil temp gauge would be wise.

I've never had a problem with the "long" input length either. Ran a SB Toploader behind a 390, a 427 and then the 427 with a 428 crank. Only in the last instance did I have the info that made me actually check the depth of the crank hole. In my case I was using a Lakewood with their block plate which may or may not make a difference.

Also haven't had to break in a Solid Cam in a long time but was present when you did on your 427 and that went without issue. I did turn my engine upside down on the stand once only to have all the lifters land on the floor. Put them back randomly and never had a problem. It was an old Cam and well seasoned so results may vary.

I've never run the stuff but there is an old saying that "Using Nitrous is like going out with a girl who has a STD (sexually transmitted disease) You want to hit it but are afraid of the consequences" 

Yes..  I have Ersons on my 390 but never had an adjuster problem The rockers seem to be the best part of that setup. Was the nut loose or you just ended up with extra lash? I'd take the adjuster and nut off and check for galling where it seats. Before that, make sure you don't have a bent pushrod. Keep us updated. Progress is always slow but worth it.