Just to recap, the fan is 3600 cfm, the t-stat is the cobra Valley 180* hi-flow which I have confirmed is in correct. I drilled an 1/8" hole in the top.
By restrictor, if you mean something that partially but not completely restricts then I see your point. I thought you meant a complete restriction. I think I now have two issues, the original problem of cool on the road but warm at idle, and now the problem casued by the shroud, which makes it heat up indefinitely without ever coming back down. I am still confused as to why the shroud has hurt instead of helped, so I will probably regress to the prior point and remove it next. Lucky for me, a new radiator shop just opened a mile east of me and I think I will pay him a visit and get an expert to confirm exactly what this radiator is and what I might need.
One thing I'd like to confirm with those of you who have an expansion tank...I removed the cap and let it heat up to t-stat opening. the flow is churing and moving but almost belching and vomiting water out in spurts. Look at this clip I just shot right after the t-stat opened and tell me if this looks right for an FE (Cobrabill, don't watch, its a DexCool volcano):