Doug, It looks like you have the exact setup I have in my 46. I'm not using a shroud and don't have a problem with overheating as long as I'm moving. When I'm just sitting the temp gage will go up into the red zone but I've never had it boil over.
I have made some modifications to my raditor also. My radiator guy welded up the stock overflow outlet that comes off the top-center of the raditor and put on a modern neck so I can use a pressure type cap. The new overflow hose comes off the neck just like a modern vehicle. One thing to remember if you go this route is to use a 7lb MAX cap. The seams in the raditor won't handle any more than that. I'm running a 7lb now but I think I'm going to change over to a 5lb just to be on the safe side.
This set up will let you run a little hotter than having a atmosphere over flow.
Keep up informed on how you doing with your shroud. I have thought about adding one to my truck but I just haven't done it yet. I'll be interested to see how you do yours.
George
