Three nitrous oxide systems were deemed suitable for this engine: a street Nitrous Oxide Systems kit (213/595-7074), a spray-bar I.C.E. kit and a Stage II 10,000 RPM kit (213/325-8848).

As good as the boost-ready short-block was, it needed a few other parts before it could even be called an engine, let alone swallow all that glorious nitrous. To complete the 408 for testing, we ...

While the nitrous bottle was being warmed up, Westech ran the 421 through its break-in program and established that the small-block made around 560 hp at 5,800 rpm and about 540 lb-ft at 4,900 rpm ...

1. GM Gen VI big-block with a 4-bolt main measured in at a 4.310-inch bore and a 9.800-inch deck height.<br /> 2. Milodon baffled oil pan (PN 30955) features an 81/2-inch deep sump to hold 7 ...