The 650 DP is a great carb. I have one on Kingsford now and its sure running like a gem
However, a vacuum secondary carb might have suited you better with that automatic. A light spring to help the secondaries open quicker and you'd probably have a more responsive car.
I'm curious to see how it works out for ya.
A 650 vacuum sec carb probably would have been a better choice in my opinion also. Also question why such a large fuel pump? I'm running pretty much the same engine combo in an 89 Ranger but with a 30 gal/hr pump and have never run the carb dry. Mines a 4 speed and previously had a 650 DP on it but have since switched to a vacuum sec 600 with a purple sec spring and it seems to work better.
There's alot of things that can be worked to make a dbl pumper perform very well on the street, without running excessively rich.
The PVRCs can be opened up slightly, allowing the main jets to be smaller for fuel mileage and excellent response without bog.
Accelerator pump cams and nozzles, etc.
The carb im getting is from a builder in tennessee.. carb is set up for street/strip..had a 600 double pumper on it before..but had a motor fire so carb was toasted.. the car ran great on the double pumper..got an edelbrock after the fire.. which is a mechanical secondary carb as well. We'll see how it goes carb should be in by next wednesday