To maintain heads-up performance status with the NHRA's mountain-motored Pros, Smith built his Rocket Olds around a virtually bulletproof diesel bare-block. Over-bored and longer stroked, the ...

First, the 403 is based on a block with a 9.330-inch deck height (as are the 260, 307, 330, and 350 engines). The 400, 425, and 455 engines use a taller block with a 10.625-inch deck height—hence the ...