fuel delivery issue

sireland67 said
What carburator are you running?
I fought heat issues with my 750 vac secondary holley all summer.
It would only start starving for fuel when it idled more than 5 minuates in temps over 85 degrees. Tried everything 1" phenolic spacer, raised the heater hose support on the front of the engine up 4".
The motor was not running hot, about 1/2 way up on the gauge.

I put a 625 street demon on it with a plastic body, and braded lines, it helped alot but it still started acting up in 90 degree temps stuck in traffic for 5 miles.
Once I drive it for a mile or so it would clear up.

I am thiniking that I also have a vent issue, because I have never had this problem before on any Mopar and I have a bunch from 1956 to present day.

I have never seen heat issues like I have on this old truck in 30 years with playing with these small blocks.

Carbs a Holley 750HP. My engine is pretty efficient so I didn't have to jet it very fat at all, 71's in the front and 78's in the back. You'd think with jets that small it wouldn't require much fuel.

I have a 1" Moroso plastic spacer under the carb and I shot the carb with the temp gun and it's actually a little cooler than the fuel pump runs. Read 150* off the fuel pump and 140* off the carb.

Know what ya mean about the fuel issues nowadays. I wonder if some of it isn't due to the Ethanol they put in the fuel?? Seems like I read something about it having a much lower boiling point than gasoline.