Hesitation
My 59 impala hesitates coming to a stop anyone knows what can it be ?

In 1959, the Chevrolet Impala went from being the Bel Air Impala to its own model. As if swelling with pride, the car grew: It was longer, wider, and more ornate, with tailfins second in size only to those on Cadillacs.
The base engine remained the 235.5-cubic-inch inline six rated at 145 horsepower, with an optional fuel-injected 283-ci V8 rated at 290 horsepower becoming the motor that all envied. Other engines are listed below.
| ci | eng | hp | fuelie | ci | eng | hp | fuelie | |
| 235.5 | I6 | 145 | n | 283 | V8 | 290 | y | |
| 283 | V8 | 170 | n | 348 | V8 | 250 | n | |
| 283 | V8 | 185 | n | 348 | V8 | 320 | n | |
| 283 | V8 | 230 | n | 348 | V8 | 335 | n | |
| 283 | V8 | 250 | y |
My 59 impala hesitates coming to a stop anyone knows what can it be ?
I have a 1959 chevy impala 283 motor that I had sitting in my shop so I swapped my 1995 c1500 v6 motor with the 283, I currently have a HEI distributor on it with the original Rochester 2gc carburetor and when I go to press on the throttle it bogs down and then picks up the RPM's, so when I go to drive it doesn't start falling on its face until 50mph at this speed it starts lugging hard so I end up backing off the throttle and down shift but some times that doesn't work can anyone help me with my problem