[Formulajones]

Originally Posted by PontiacHO

Here’s some more info…drove it a little while ago. Outside temperature is already in the mid-eighties. Stopped at the gas station and refueled with 93 octane. It did not want to restart. Seemed the carb may have been dry. Got it started and drove towards home. Wound it up a couple of times and no stumble. It ran fine. Got home and pulled the air breather. The fuel was percolating in the carb. Temperature gauge showed 180 degrees when I parked in the garage. Could this be causing the stumble? Maybe needs a carb to intake insulated gasket? Maybe it needs the fuel return line from the pump to the tank? I do run more initial timing than I may need at 18 BTDC. Vacuum advance is ported vacuum. No spark knock or labored cranking. Dunno but it shouldn’t be boiling the fuel. The heat riser flap was removed from the exhaust manifold but the intake crossover is not blocked. Stock cast iron intake (68-71).

When you have a heat cross over blowing 500+ degree exhaust temps under a carb with today's fuel, it for sure will cause all kinds of drivability issues in the summer heat.

I'd still have a gauge on it to see how it's acting but it already sounds like there are a few things I'd be addressing on it.