Will a 1993 suburban computer work in 1990 1500 pickup?

No, a 1993 Suburban computer (meaning the vehicle's onboard computer system) will almost certainly *not* work in a 1990 Chevrolet 1500 pickup. The computer systems and their associated wiring harnesses are entirely different. Even if you could physically fit it, the software and communication protocols would be incompatible. You'd need a computer system designed for the 1990 model year truck.