Hemi Swapping a perfectly good 70 Duster

My gates hose clamps came in Saturday so I was able to get the heater hoses and power steering suction line completed and get fluids topped off. I ran the car on and off for about an hour until my wife had enough of the open headers. Apparently it was rattling the walls in the house. Hmmm, I didn't notice... I'll get the exhaust back on before I run it again for any length of time. Ultimately the exhaust is the last big thing to get done.
I welded the IAT bung in the intake tube along and a piece of flat bar that I will use to attach a bracket to hold it up. Still need to Cerakote the tube, the rain has been ridiculous here so I couldn't get that done. I'll get some final pics once I get everything tidied up.
One thing that I noticed while running the engine was how much better the engine cooled. Once the radiator fans kicked on, the temperature almost immediately dropped low enough for them to turn off. I don't know if its the more efficient cooling system of the engine, or the double pass radiator. Perhaps its a combination of both. My 408 would just hold temp when idling and not moving, not drop temp! Looks like I'll be good for the 100 degree days in traffic with the AC on.
As I mentioned above, the IAC is a Pain in the *** to get set right. I don't know if its a megasquirt thing or not, but it just sucks. The big part is, there's not feedback on them, so the computer doesn't know what position it is in. There's lots of moving it in and out and unplugging and reinstalling... I did some fiddling with it yesterday without the engine running and I think it should be good now. When I was finally able to get the idle down to 800-900 RPM the cam sounds like it will have a decent lope. If its too much, I'll tone it down with some idle advance settings. All that's required to tone it down is to retard timing when the RPM increases, and advance it when it drops. You can also make a cam sound more aggressive doing the this. None of those advanced settings are active right now.