We have located a few NOS pieces of the original GM Performance Parts Camaro 350 HO ZZ4 engine conversion computer PROM or chip (GM part number 24502456). This calibration has a high performance spark curve and carburetor duty cycle optimized for the ZZ4 crate engine. The chip also raises the speed at which the torque converter clutch is applied for improved drivability. Since the ZZ4 Camaro package was emissions-certified without using an EGR, the EGR functions and diagnostics are turned off to avoid false check engine lights for EGR related diagnostic trouble codes. This calibration is for 1985-87 Camaros and Firebirds that were originally equipped with the LG4 (VIN H) or 1983-86 L69 (VIN G), ESC system, and 700R4 (4L60) four-speed automatic transmission. PROM holder is included, but not shown in photo for clarity.

We have located a few NOS pieces of the original GM Performance Parts Camaro 350 HO ZZ4 engine conversion computer PROM or chip(GM part number 24502457). This calibration has a high performance spark curve and carburetor duty cycle optimized for the ZZ4 crate engine. The chip also raises the speed at which the torque converter clutch is applied for improved drivability. Since the ZZ4 Camaro package was emissions-certified without using an EGR, the EGR functions and diagnostics are turned off to avoid false check engine lights for EGR related diagnostic trouble codes. This calibration is for 1982-84 Camaros and Firebirds that were originally equipped with the LG4 (VIN H) 305 four-barrel engine, and 700R4 (4L60) four-speed automatic transmission, without ESC. PROM holder is included, but not shown in photo for clarity.

We have developed a five-speed manual transmission version, based on the original GM Performance Parts Camaro 350 HO ZZ4 engine conversion computer PROM or chip. The chip incorporates shift light logic that turns the factory shift light on at 5800 rpm for optimum performance and improved engine durability. This calibration has a high performance spark curve and carburetor duty cycle optimized for the ZZ4 crate engine. Since the ZZ4 Camaro package was emissions-certified without using an EGR, the EGR functions and diagnostics are turned off to avoid false check engine lights for EGR-related diagnostic trouble codes. This calibration is for 1985-87 Camaros and Firebirds that were originally equipped with the LG4 (VIN H) or 1983-86 L69 (VIN G), ESC system, and five-speed manual transmission. PROM holder is included, but not shown in photo for clarity.

We have developed a five-speed manual transmission version based on the original GM Performance Parts Camaro 350 HO ZZ4 engine conversion computer PROM or chip. The chip incorporates shift light logic that turns on the factory shift light at 5800 rpm for optimum performance and improved engine durability. This calibration has a high performance spark curve and carburetor duty cycle optimized for the ZZ4 crate engine. Since the ZZ4 Camaro package was emissions-certified without using an EGR, the EGR functions and diagnostics are turned off to avoid false check engine lights for EGR-related diagnostic trouble codes. This calibration is for 1982-84 Camaros and Firebirds that were originally equipped with the LG4 (VIN H) 305 four-barrel engine, four- or five-speed manual transmission, without ESC. PROM holder is included, but not shown in photo for clarity.

We have developed a calibration for the 1988 Monte Carlo LS or SS based on the original GM Performance Parts Camaro 350 HO ZZ4 engine conversion computer PROM or chip. This special chip works with the revised valve body hardware in the 1988 2004R transmission and permits correct TCC operation. This calibration has a high performance spark curve and carburetor duty cycle optimized for the ZZ4 crate engine. The chip also raises the speed at which the torque converter clutch is applied for improved drivability. Since the ZZ4 Camaro package was emissions-certified without using an EGR, the EGR functions and diagnostics are turned off to avoid false check engine lights for EGR-related diagnostic trouble codes. This calibration is for 1988 B and G-body vehicles that were originally equipped with the LG4 (VIN H) or L69 (VIN G) V8, and 2004R four-speed automatic transmission. PROM holder is included, but not shown in photo for clarity.

If you have installed a new crate engine or high performance Chevy small/big block in your 1982-88 GM B-, F- or G-body vehicle that was originally equipped with a 305 or 350 quadra-jet Chevy V8, we can create a custom chip specifically for your application. This PROM will allow you to retain the Q-jet carburetor, HEI distributor and torque converter clutch functions for great performance and maximize fuel economy. Complete the Closed Loop Carburetor Custom Calibration Worksheet and email or FAX it to us before ordering this chip. Adobe Acrobat Reader required to view this worksheet. Click here to download Adobe Acrobat Reader. PROM holder is included, but not shown in photo for clarity.

If you have installed a new crate engine or high performance Olds small block (350, 403) or big block (455) in your 1982-90 GM B-, or G-body vehicle that was originally equipped with a 307 quadra-jet Olds V8, we can create a custom chip specifically for your application. This PROM will allow you to retain the Q-jet carburetor, HEI distributor and torque converter clutch functions for great performance and maximize fuel economy. Complete the Closed Loop Carburetor Custom Calibration Worksheet and email or FAX it to us before ordering this chip. Adobe Acrobat Reader required to view this worksheet. Click here to download Adobe Acrobat Reader. PROM holder is included, but not shown in photo for clarity.

This remanufactured engine computer or ECM was originally used on 1987 and ‘88 GM vehicles with 305 and 350 four-barrel Chevy small block V8 engines. This engine control module replaces earlier computers found on 1982-86 GM Vehicles with 305 and 350 four-barrel Chevy small block V8 engines. NO modifications to the ECM wiring or connectors are required to use the computer on 1982-86 applications. The newer computer features software upgrades, improved diagnostic capabilities and circuit board components. This ECM is required for use with the above engine computer chips or PROMs. This computer does not contain a PROM. It must be transferred from an old computer.

This USED, tested, good engine computer or ECM was originally used on 1987 and ‘88 GM vehicles with 305 and 350 four-barrel Chevy small block V8 engines. This ECM will replace earlier computers found on 1982-86 GM vehicles with 305 and 350 four-barrel Chevy small block V8 engines. NO modifications to the ECM wiring or connectors are required to use the computer on 1982-86 applications. The newer computer features software upgrades and improved diagnostic capabilities and circuit board components. This ECM is required for use with the above engine computer chips or PROMs. This computer does not contain a PROM. It must be transferred from an old computer.

This remanufactured engine computer or ECM was originally used on 1984 GM vehicles with 305 and 350 four-barrel Chevy small block V8 engines (engine VIN codes G, H, and 7). This computer does not contain a PROM. It must be transferred from an old computer.

This remanufactured engine computer or ECM was originally used on 1985 GM vehicles with 305 and 350 four-barrel Chevy small block V8 engines (engine VIN codes G, H, and 7). This computer does not contain a PROM. It must be transferred from an old computer.

This computer calibration was developed to allow the installation of the 502HT crate engine into a 1991- 93 GM C/K series truck that was originally powered by a 454 L19 big-block engine and 4L80E four-speed automatic transmission. It has a premium fuel spark curve for maximum torque and horsepower. The fuel curve is revised to provide the correct fuel flow with GMCOPO's fuel pressure regulator and the increased horsepower of the 502 HT engine. The transmission portion of the calibration has higher shift points and firmer shifts to ensure crisp transmission operation when used with GMCOPO's spacer plate/drain plug oil pan kit.

Tired of looking at the Check Engine Light since you have installed a new camshaft in your LS1 GTO? Wishing that the speedometer read correctly after the 4.10 gear set was installed? Want to install larger fuel injectors? Tired of soft automatic transmission shifts in your 5.3 truck? No problem, just complete the Port Fuel Injection Custom Calibration Worksheet prior to placing your order and we will revise the calibration to complement your hardware revisions. Adobe Acrobat Reader required to view this worksheet. Click here to download Adobe Acrobat Reader.

We can provide a custom powertrain calibration for street machine and street rod applications. Putting an LS2 in a 1967 Chevelle? Dropping a new LS7 crate motor in a 1955 Chevy? No problem, just complete the Port Fuel Injection Custom Calibration Worksheet prior to placing your order. Adobe Acrobat Reader required to view this worksheet. Click here to download Adobe Acrobat Reader.

GMCOPO has developed unique calibrations that complement our camshaft and engine kits. Please complete the Port Fuel Injection Custom Calibration Worksheet prior to placing your order. Adobe Acrobat Reader required to view this worksheet. Click here to download Adobe Acrobat Reader.

GMCOPO can go to your location and custom tune your vehicle. Please complete the Port Fuel Injection Custom Calibration Worksheet and give us a call to discuss your tuning needs. Adobe Acrobat Reader required to view this worksheet. Click here to download Adobe Acrobat Reader.