Have a new 406 small block in my 70 Chevelle and it runs really well till about 3/4 throttle then it has a terrible bog. I had the same intake and carb on my 350 last year with no problems. Carb was new last year. 650 AVS with electric choke.
The intake is a weiand stealth. HEI and nothing really fancy. I just put a new fuel pump on it this morning and made a hard line from the pump the the line from the tank. (thought it might be sucking it closed)
Anyone have any suggestions?

LK

my old 70 skylark did that when i swapped it two a edelbrock 650 four barrel from a two barrel... i think mine was running to rich and just got too much gas when floored? it only happened a couple of times... Other than that Im not sure what else to check :/ timing and such...maybe bad plugs or wires?

Timing is correct, Looked for vacuum leaks. Does anyone know what feeds the secondaries on an edelbrock? Seems like the secondaries open up but there is no fuel so it goes lean. (like a vacuum leak) I think something may be plugged or stuck from sitting on the shelf in the garage for 6 months.

LK

You Mentioned Bog In Your First Statement Then You Mentioned It May Not Be Getting Fuel When The Secondaries Open Up. Does It Get Quiet When You Floor It Or Does It Studder?

It does not studder, I can go to 3/4 throttle pretty well and then when I put it to the floor it sounds like the secondaiies are opening but the car does not accelerate, In fact it might slow down.
I took the carb apart and made sure there was no crap inside, Looks like new (as expected) I tried a different dist cap just for the heck of it and no change. Both float bowls were full when I took the top off the carb and both floats are adjusted correctly.
Any edelbrock experts out there? I tried the tech line but it was giving me a busy signal untill they were closed then I got a recorded message, Go figure.

LK

Timing not advancing correctly maybe? Do you have a vacuum advance, and is it functioning?

That's the only thing else I can think of of the top of my head.

Good Luck.

Did you run a 3/8 line from the tank to the pump to the carb?

I believe it's 5/16 but I will check. Was a small block v-8 car orig. Can you change the line without getting a new sender?

LK

Really sounds to me like you run fine on the primaries and your problems start when the secondaries start to open. I would increase the spring tension on the secondary butterfly a bit and see if it makes it better.