Whats the difference ? 4150 question !

PRH said
The 1.600 x 1.750 body with the fancy annular boosters was the worst carb we tried.
Very very rich at part throttle........ and too lean to make a pull at wot.

Added a bunch of jet to it, which made the part throttle even worse, but the wot was still too lean to pull it into the upper rpms.
That was the second carb we tried...... after we saw how far off it was, we moved on to another one.
Click to expand...

interesting.... what I found with my 4825 (1.48 venturi/ 1.79 throttle plates from a few pages back) is that if the DA went below 800ft it would go lean. Of course at the track all we had were jets and 99 was the largest we had.... no bueno. This carb still used power valves too. Prob would have looked into it more, but we moved on to a 4500.