LOwer your pressure. Your gauge might be wacky.
The empty bowl is from the fuel percolating out when you shut it down. Depends how hot it gets determines how much is left.
What's the elevation where you live?
You might need to lower your floats a bit.

 

Check to make sure your needle/seat are sealing. On one of my carbs the seat was milled a little deep not allowing the needle to seat and seal, required two seat gaskets to raise it slightly and allow the needle to seal correctly.
Also check to make sure your transition slot is not uncovered to much (throttle stop adjustment).
Have met a lot of carb pro's that talk a good story but actually know less about carbs than I do, and that ain't saying much...
Just re-read your post where you said "you didn't change float needle and seats". Always change the needle and seat!

 

I lowered the pressure to 4 psi. Will see how that works. Elevation here is 360 ft ASL, (north of Houston, Tx)

The carb to intake manifold gasket is thin 3/32 in. Is there a thicker gasket ? Some guy told me the other day about him having to get a thicker spacer for lowering carb-heat. My previous carb was a Rochester Quadra-jet & I had no problem with losing bowl-fuel-level. (As I remember)

Paul Hillman

 

Got the truck running this AM, at 4 PSI & the first road test was OK, but it screws up with longer running time & heat build-up. If problem persists will change float needle & seats.

This 1406 is on a '79 chevy C-10 pickup with a 350 small block.

Thanks, Paul Hillman

 

You need a heat spacer.
Here's some.
https://www.summitracing.com/int/search/product-line/edelbrock-carburetor-spacers

 

If it is like my '75 350, from the factory your Quadrajet probably came with a spacer that is about 3/8" thick. You should try using at least a 1/2" spacer with the Edelbrock to give you some heat insulation, and you might even use a thicker spacer. Use one made of phenolic or wood, not metal.

Bruce

 

X3 on the spacer. This is getting too much heat from the intake into the carb body. Houston is one place where an air gap makes sense. Check the exhaust system some of these trucks have a heat controlled valve at the exhaust manifold to head pipe joint that is intended to speed warm up by forcing exhaust through the intake's crosser over . If this gets stuck closed the intake gets really hot.

Bogie

 

not to pile on; but I like the CoolCarb spacer for the Edelbrocks. But as the website (now) states "not for intakes with EGR or heat crossovers" That localized hotspot will deform the poly inner core.
Order Products
Hot start issues? GONE. And they only take up less than a quarter inch.
The marina I worked at installed a lot of these on ski boats, a lot with Edelbrock or Carter carbs. Towing a skier generates a lot of heat. Skier falls down, boat stops, putters back to skier and turns off...has trouble restarting. Class racers love the ones marked "same size as gasket". LOL