Yes it will. 1978-'88 G-body Malibu and Monte Carlo used smaller than the earlier Chevelle's SAE calipers. These metric calipers and rotors are used in most aftermarket disc brake conversions kits because the parts are plentiful (making them cheap). The G-body shares a lot of parts with the earlier A-boy Chevelle but the cars shrank in size to improve mileage. By making a car smaller it becomes lighter. A lighter car isn't a great choice for brakes if you have a heavy full size car. The brakes got smaller because there was less weight to drag to a stop from highway speeds.
Speedway sells a cheaper than Wilwood or Baer caliper alternatives for circle track racers that also fit your existing drop spindle.
https://www.speedwaymotors.com/Spee...re-1978-88-GM-Metric-Brake-Caliper,25158.html
This yields a better caliper on par with the earlier Chevelle, but you still have the thinner lighter rotor that will fade faster than a larger thicker rotor will (with brakes you want weight to act as a heat sink). More metal means it can absorb more heat before brakes fade. This is why the Corvette uses 13.4' inch rotors (the JL6 option used on the Z05 model moves the caliper out closer to the edge for more are per revolution) that are a quarter inch thicker than the Impala rotor (1.26" vs. the lighter 0.875" Impala rotor thickness).
With Brakes and engines bigger is better! But only you know how you will drive your car. Is the heavier duty Wilwood or Baer unit worth the extra money knowing the G-model brakes are only marginally better at brake fade than the stock drum brake.
Another alternative is to use the C6 Corvette Steering knuckle and spindle on your Impala:
https://www.ebay.com/itm/A-F-X-BODY...307?_trksid=p2349526.m4383.l4275.c10#viTabs_0
Then you can use stock Corvette rotors and calipers (which requires larger diameter wheels to clear the larger diameter rotor).
Another alternative is the 1977-'90 Impala 9C1 Police front steering knuckle (also used on the station wagon). It has a 12 inch rotor that uses the same smaller metric caliper but it is mounted further out for better stopping. This rotor requires 15 inch vented Police steel wheels that are stronger than stock steel wheels (but are also heavier).
Big Dave
Speedway sells a cheaper than Wilwood or Baer caliper alternatives for circle track racers that also fit your existing drop spindle.
https://www.speedwaymotors.com/Spee...re-1978-88-GM-Metric-Brake-Caliper,25158.html
This yields a better caliper on par with the earlier Chevelle, but you still have the thinner lighter rotor that will fade faster than a larger thicker rotor will (with brakes you want weight to act as a heat sink). More metal means it can absorb more heat before brakes fade. This is why the Corvette uses 13.4' inch rotors (the JL6 option used on the Z05 model moves the caliper out closer to the edge for more are per revolution) that are a quarter inch thicker than the Impala rotor (1.26" vs. the lighter 0.875" Impala rotor thickness).
With Brakes and engines bigger is better! But only you know how you will drive your car. Is the heavier duty Wilwood or Baer unit worth the extra money knowing the G-model brakes are only marginally better at brake fade than the stock drum brake.
Another alternative is to use the C6 Corvette Steering knuckle and spindle on your Impala:
https://www.ebay.com/itm/A-F-X-BODY...307?_trksid=p2349526.m4383.l4275.c10#viTabs_0
Then you can use stock Corvette rotors and calipers (which requires larger diameter wheels to clear the larger diameter rotor).
Another alternative is the 1977-'90 Impala 9C1 Police front steering knuckle (also used on the station wagon). It has a 12 inch rotor that uses the same smaller metric caliper but it is mounted further out for better stopping. This rotor requires 15 inch vented Police steel wheels that are stronger than stock steel wheels (but are also heavier).
Big Dave
