427 tri carb runs poorly after warmup
My friend owns an original 69 Vette with a 427 tri carb set up and 4 spd. It's a total restoration to original specs. It's a beautiful car.
The engine starts great and runs fantastic until it reaches operating temp, about 185, then it acts like it is suffering from vapor lock. He lets is cool down and it starts back up with no problem and runs like a scald rabbit until, again, it reaches operating temp.
So far he has insulated the fuel lines, replaced the spark plugs, plug wires, rebuild the carbs, checked the timing, checked for vacuum leaks, replaced a power valve..... you get the picture.
I don't know what distribtor he's running at this time, I'll find out.
Does anybody have any suggestions? Is there any other information I have left out?