I recently rebuilt my 4300 carb (1st time for me). After reinstallation it seems that the car always runs in fast idle mode. Also the more I open the choke plate the higher the rpms go. Any thoughts.

1971 Mach 1, 351C

 

It's been a LOOOONNNGGGG time since I have looked at a 4300 but it sounds like it might be a linkage issue. Make sure you have all the right linkage rods in the correct places and nothing is binding.

 

the 4300 is a really sucky carb, its like a ford quadrajet and the quadrajet is way better, put it on the shelf, sell it and get a demon or holley or edelbrock in that order.