1984 Rampage used a rod shifter and small spline axles. All A-555's were cable shifted and had large spline axles. The trans will bolt on the engine and fit the clutch but you will need large spline axles. 1988-1990 Omni/Horizon Automatic axles will work fine and it's been recently found that Dynasty axles will also work. Ther are kits available to modify your rod shifter to work on the A-555 but most use the shifter and cables from a 1987-1989 A-520/A-555 Shadow/Daytona etc. Due to gearing the A-555 will increase highway engine RPM.
Thanks
Randy