Well, a '91 Z28 could also have a LB9, which is a 305. Two versions were made, one with 205 net horsepower, 285 lb-ft torque; the other 230 net horsepower, 300 lb-ft torque.
The '91 L98 was rated at 245 net horsepower, 345 lb-ft torque. For the record, it was a 4" bore by 3.48" stroke, which if you do the math comes out to 3.49.8 cubic inches. Typically rounded off to 350.
All of these were first generation series small block Chevys. All had Tuned Port Injection, or TPI.
That's assuming it is a Z28.
The LT1 and LT4 are considered 2nd generation SBC. LS1/2/6, 3rd generation.