Working on my uncles 1970 Charger with a 440 and 727. He recently had a Holley Sniper kit put on by a shop in town and long story short they did half *** work. I am a mechanic with 10 years under my belt and after this last shade tree work have full oversight into anything that will be done to this beautiful car. EFI has Holley tank as well. My uncle has told me that when it gets hot, since the EFI install, 219 or higher the car stalls. Today after doing a few more repairs/ maintenance I noticed at a light on the Holley display it hit 220. It stalled at the light in gear about 15 seconds later, started right back up and left light. I felt it running off and continued to where we store it. I was 200 yards away cruising at 55 mph and it shut off completely, Holley display showed 219 at time. I was able to coast to where I was going and let it sit for about 1 minute, started right back up and parked. My question is, what am I missing??? It does not have electric fans and has been completely restored. I drove it on 2 20 mile trips the day before with zero issues and only reached 213 degrees before this. Looking for a little guidance on what to look at going forward, obviously don’t want this car dying going down the highway again. Any info, advice greatly appreciated

 

Why is it running so hot? 180 to 190 should be hot enough.

 

I agree. Thats a little Hot...
I would suggest: Check the Vacuum, Check The Fuel Curve, And see what the Air Fuel Ratio is when it is hot.
Unless you have a loose wire someplace?