I thought too much timing would make them run hotter? Had a 69 Roadrunner i tuned up for a guy about 35yrs ago. The 383 in it always ran hot after i gave it a super tune which was a dist dissemble,cleaning and a good recurve with the lightest springs i could find installed, cranking timing up and a carb rebuild. Ran great,but always ran hot. Never figured it out and yrs later i start hearing about too much timing causing an over heat issue. Figured thats what it was.