Maybe I am not understanding you correctly. I wouldn't lower your timing numbers, crank it up! If you are at 15* , then it's only giving it 3*over what you have set with the distributor. Turn it up 5* at a time and see what happens.
Late timing can make it heat from what I have seen.
I have my idle timing set somewhere around 26 like @6872xtc
Thanks for all the input on timing. You never know it could be causing some of the heat. Just got the fan delivered today so now I have to pull the damn radiator out to mount it up. Fun fun. I just want to drive the damn thing. Is that too much to ask for? LOL
Really appreciate it guys!!
Also, looks like Edelbrock can walk you through the PF4 settings on your engine just to be sure things are dialed in correctly. I might give them a call during the week.

(requires 2). Luckily I was able to put those in the wheel while in the tire. I get ahead of myself especially when I'm tired and its late...