Changed carb and lost power...HELP!

[eastcoastcivil]

I have a 67 SWB 1/2 ton Chev with an engine built at a race shop. 350 four bolt bored .30 over, Energizer cam, hydraulic valves, edelbrock intake, Edelbrock 600 carb, headders, flowmaster 40 series with 2.5 inch pipe, 3.73 in the rear and a 400 turbo with a 2400 stall and a shift kit.

The truck has lots of bottom end and takes off real fast...heres my new problem.

I put a 750 Edelbrock carb with non stock metoring rods on and found that it didn't have the same power at all (Take off). It was off a high compression chevelle 350.

I took it off and put the 600 back on but installed a 1" spacer... I thought that it would take off the same as before all this but it wont. I have all kinds of top end though.

I want to have my bottom end back...I want to be able to run 1/4 mile on the streets like I used to. What should I do? (Which combination)

Thanks