engine bogging cant figure it out

[19charger72]

So just finished fixing blown head gasket. I take it down the road cruzing at 2500 rpm I put my foot in it and it is delayed and bogs till the rpm gets up to 3500 4000 then takes off like a rocket. I have adjust float levels changed the timing, changed ballist resistor, checked for vacum leaks and still no success.

Im running 440 bored .060 over .495 lift comp cam (ill have to check for duration), mallory dual point distributor, edelbrock 750 performer carb, mechanical fuel pump.

Cant find the problem any suggestion, idea, etc. would be great.

Thanks
AK