Sounds like you are on the right track here. With my dad's truck once you got over the stall from lack of fuel the engine would catch and go... I mean really go. Getting enough fuel was the trick. The 600 did just fine on the old engine and would move the truck around pretty good unless you punched it and then it would fall on its face. New carb and you would have to be careful at launch, squack into 2nd and a chirp into 3rd. I also broke loose once from 30mph and left some new stripes on the street.

Massey

 

I had so much bog on my 327 when I first installed the tunnel ram and dual 450's that it would kill the engine if I hit it full throttle. If I went half throttle it ran great, and if I eased into it the engine performed even better!
I replaced the pumps with 50cc squirters, and readjusted the timing, now it runs like a scalded dog, and no bog at all.

 

I agree you may need a bigger carb.
Remember to check float levels. My car fell on its face on launch
for quite a while. Turns out float levels were off.

To much fuel will cause the same as to little fuel off the line.
But I doubt you are getting to much fuel.