Cooling issue (revisited)

So I had a post a while back about a cooling issue on my 74 Challenger, 318/904 car mild cam, cast iron 4bbl manifold, Carter AVS, Magnum exhaust. With 2 core aluminum aftermarket radiator, I couldn't keep it under 220 - 230*. Switched to a 3 core and I can run 200 and under even with a 180* thermostat. However, after about a half hour run, (Good and warmed up), it starts crapping out at WOT, stalling at stops and hard to re-start. I believe its fuel starved. It starts long enough for the started to quit turning then dies. After several attempts it will start but run but erratically. Misses and runs rough at anything over an idle until its cool again.

Question: Will a weak fuel pump act this way when it gets hot? Carb too hot and boiling fuel in bowl? Timing issue; Weak advance springs? Runs great at first but tends to feel starved at WOT

Thanks
Scott

not likely a fuel issue.
since it will run for a while normally first.

you probably have an ignition issue.
but you can test yourself, by manually using a lower gear so you have higher rpm than normal and try wot say in first gear. see if you still have it early before it heats up.
if it doesn't do it, then it isn't fuel.

Scott what ign do you have?

Sounds a bit like vapor locking but could be a heat sensitive ignition component as well. You're not running ethanol based fuel are you ??

Robert, its just a stock ignition

Yes, actually I do tend use ethanol

That's good news. Was it acting up when you had the cooling issue?

Yes. I assumed at that time, it was a heat related issue. In fact, with the 2 core radiator, on a couple occasions, it seemed to get so hot, it shut down and wouldn't restart for a couple hours. BTW, I have a new temp gauge, finally. The old one was sticky and never did go all the way to 0*

Ethanol based fuels have a lower boiling point than non ethanol fuels and can wreak havoc in older carbureted vehicles with the temperatures we've been experiencing. \
I would start by getting it out of the system ASAP. Other changes may also be required if it is vapor lock and changing fuel does not resolve the issue.

Just to eliminate the ignition system:
The only thing I could move is the coil. Everything else is on the firewall. Any advantage to having these components on a fender-inner instead of the firewall?

Scott