Timing is part of the issue and I agree you have other problems but, why would you only have 5 deg of advance at idle? Don't you have a vacuum advance? I wouldn't have any less than 20 at idle, preferably more with a vac advance.
Why would you think timing is the issue? If it over heated no mater were the timing is??? That makes no sense. And that is 5 deg is initial timing. That is set with the vacuum advance un hooked. Factory spec is 0 deg. Or top dead center for 1973. So that should not have a thing to do with it. Yes on a performance engine I would run more timing. But on a stock 318 2bbl there is no need. Believe me I have checked a thing or two. This is not my first rodeo. May only be my second Mopar, but I have had over 20 classic cars in my life time. And raced quite a few rather heavily. Not to mention retired from a corporate flight department were I kept 30+ mill aircraft in the air and operating correctly. Not tooting my own horn or anything, just trying to give the bigger pic. Boils down to I just did not know how close the fan should be the the radiator. Now that I found the seems to be imposable to find shroud for one, I am sure it will fix the problem. Just can not wait for it to get hear!
