The L98 is the 5.7-liter sibling of the LB9 — same architecture, longer stroke, the GTA's standard engine. By 1991 it was rated 245 horsepower net at 4,400 rpm and 345 lb-ft at 3,200 rpm. Same TPI long-runner intake; same port-injection metering; same 4L60 automatic in most GTA pairings.
Compared to the V-code 440 Six-Pack, this engine is roughly half the displacement — 350 versus 440 cubic inches — and rated in net rather than gross horsepower. A direct comparison: the V-code engine made 390 hp gross, the L98 made 245 hp net. Apples and oranges in headline numbers, but in 0–60 times the gap is much smaller than the rating delta suggests, because the GTA is two decades of development newer, smaller, and lighter, with much better fuel metering, ignition control, and gearing.