Ok Falcon, no harm no foul. What you say makes sense, I just didn't know that was the point you were driving at because I hadn't heard that theory before. But I see what you mean about the carb. And I learned something new, so thanks. I do appreciate that sort of advice.
In fact when I got the head back from the machine shop my first thought was they must have put my adapter plate on backwards, because it did look odd. For mounting convenience alone it might have been better the other way, but the shop did a poor job of consulting me and the way they attached the plate it's permanent, so it is what it is and I can't change it now. I've done many things backwards on this build but honest, that was theirs not mine!
I do appreciate advice though, and I need all I can get. Before I started this project I had honestly not even changed my own oil. I'm mechanically inclined but I lack experience with cars. I just had this car and I knew I wanted it to perform better and I wanted to work on it myself. I've wished so many times I had someone around locally who could show me the ropes. You can read descriptions on the internet but when you get into the engine, unless you've done something before, the first time is always confusing.
I easily could have avoided the issue with my head now if I knew physically how little pressure it takes between the pushrods and the arms. I thought it had to be tight so I wasn't surprised I really had to wrench down on the rocker assembly just to get it installed. Yeah, I noticed some of the springs were compressed, but hey, some of them would have to be, so what do I know? I think I bent some rods just getting the rocker shaft bolted on. That would have been a clear sign to anyone else, but I just didn't know.
It all makes sense now, after the fact... terms like "preload" have a real meaning that I didn't understand previously. When I got my shorter rods I was shocked that I was able to bolt my arm assembly completely down to the head just by turning the bolts with my fingers. So that's how it's supposed to be! Too bad I had to toast my valve seals to find out...
I've learned a lot about this engine - but almost all of it the hard way. I know it's embarrassing to watch, but you have to be a noob at some point!
Luke