Okay so i have mixed many an issue with this car.

-Timing is correct
-Fuel pressure is around 3.5 psi. (gauge gets jumpy between 3 and 4 but stable higher or lower than that. no idea why). its not the pump
-Jetted per what Racing Beat wants for a 13b 6port stock engine. The carb was running on a 12a streetport for years and ran wonderfully.

The car idles odd when i play with the idle adjustment screws. And for the most part its good with medium speed acceleration enrichment. But quick stabs makes it fall flat on its face. That is with no load mind you.

Car runs great wide open above the 2300 mark.

So it seems like i need more acceleration enrichment. But frankly, i have no idea how to do that.

Could it be the needle valve? Im running a 300 that looks like the the first pic, but i do have some 330s like in the second. I frankly have no idea what the change means or does.

 

13B Engine (6-Port)
Venturi - 40mm • Fuel Jet - No. 195
Air Jet - No. 205 • Emulsion tube - F-4
Needle Valve - 300

 

still working out flat spots.

pump jet size is probably too small (50) but finding larger ones is impossible

 

Do you have the screw in type of the push style? I might have some extra of both in my garage. What you described definitely sounds like a flat spot due to not enough pump shot once you crack the throttle open. If you can't find them let me know and I can drill out your existing ones or sell you a pair drilled to the correct size.

 

50 is too small, 60 to 70 much better. try cleaning them out with brake cleaner first but likely they need to just be larger.