Mine is heating a bit too - put about 250 miles on it this weekend. Only when I'm sitting in traffic (it was 93 deg and high humidity aka miserable) or climbing a long hill (like up to 6600 ft this weekend - highest peak east of the Mississippi). Been bouncing back and forth about installing one of the "$$$ gold plated" fan shrouds.
Has a new radiator, water pump, and a flex fan from a 72ish Tbird. The fan sucks a lot of air at idle but much quieter on the interstate.
My Damper finally failed and I had to replace it. The new engine pointer was different than the old 352 so I haven't had a chance to check the timing closely. I just marked where I thought was TDC on the damper (by using a tube in #1 cyl and feeling the piston movement) and the pointer already on the timing chain cover.
Hopefully the timing adjustment will cure your problem...... and mine too.
Guess you are you adding an extra transmission cooler other than the one in the radiator?
You've always got great information on your repairs - looking forward to hearing what works. (and wishing I had copied your cup holder sooner - would have been nice this last trip)
Big fan - I've since painted it white to look original. Only about 1/4 inch clearance to the expansion tank. Only helped a little at idle/low speeds.