Stalling Issues at operating temps.

[Tankiteer]

Picked up a 1981 GMC C1500, swapped out the original inline 6 with a '72 350 Rocket. Motor runs amazingly at colder temps, has zero issues pulling at anything below 180. After that, the motor starts sputtering under load. If the gas pedal is pressed any more than an eighth or so inwards while in gear it bogs very badly, and stalls out sometimes. Even idling becomes an issue around 190+ as the motor starts having major issues continuing to run, dropping cylinder by cylinder before dying. Can't seem to find a fix, so I figured I'd ask here. (Rochester 2gc carb, 16 gal tank (reads as 10 tho...?))

 

[NLD79K10]

Seeing as it seems to be engine temperature related, I'd start with checking the temperature of the carburetor float bowl as it could be as simple as the fuel in the float bowl percolating. Alternatively it could be a vacuum leak at the ported vacuum switch or a heat related issue in the ignition system such as the HEI module, pickup or the coil.

 

[Tankiteer]

Seeing as it seems to be engine temperature related, I'd start with checking the temperature of the carburetor float bowl as it could be as simple as the fuel in the float bowl percolating. Alternatively it could be a vacuum leak at the ported vacuum switch or a heat related issue in the ignition system such as the HEI module, pickup or the coil.

i do know my float's been getting stuck, and quite a bit of fuel has flooded onto the top of the motor. ill check that soon, thanks mate!

 

[Grit dog]

1 16 gal tank?
That’s brutal….

 

[Tankiteer]

1 16 gal tank?
That’s brutal….

oh yeah, especially getting maybe 6 miles per gallon ive got a buddy with a 20 im gonna take off his hands, shes a work in progress