When you’re speaking about rare Chevys, there are many factors that can set a particular car apart from the pack. In the case of Roger Sortino’s 1963 Z-11 Impala, there are several that contribute to the car’s rarity. Sure, only a few more than 50 cars were produced with this ultra-high-powered option, but what sets Roger’s Chevy apart is what all transpired since it left the factory.
Making A Z-11 Impala
One of the biggest deviations from other common-production Impalas built in ’63 is what the General called Regular Production Option (RPO) Z-11. These cars were dreamed up in the minds of enthusiastic automotive engineers and were signed off on by executives who wanted to give their customers whatever they wanted. These cars made their mark just as the muscle car era was starting to pick up steam, and interestingly, they stood as the pinnacle of performance for some time afterward.
RPO codes are company-wide designations for options or packages. In 1963, Z-11 was the highest-performing Impala you could purchase.
Beginning as a top option in 1958 within the company’s Bel Air line, the Impala’s price tag included special trim, a deluxe interior, and the option of a 315 horsepower, 348 V8 engine. Due to its popularity, Impala became its own distinct model the following year and sales numbers and performance continued to soar. The Super Sport badge appeared in 1961, and true to its name, only the higher-performing 348 engines, or the then-new 409 could be had within Impala SS trim.
GM engineers were trying to squeeze more performance into the proven “W-engine” by boring and stroking the engine to make the ever-popular 409 powerplant. In addition to more cubic inches, GM’s in-house power merchants also added an aluminum intake manifold wearing a four-barrel carburetor, solid lifter camshaft, and an 11.25:1 compression ratio. GM built one good thing upon another by adding second carburetor atop the 409 in 1962. With the additional fueling of dual, four-barrel carbs and a new, lighter valvetrain, the 409 now produced an impressive one-horsepower-per-cubic-inch. It wasn’t the first engine to claim this ability, but it was the largest one to date.
The “W-motor” grew in size from 348 cubic inches early on to a competition-shattering 427 cubic inches in the Z-11 package.
Chevrolet was on a roll, and the very next year, GM engineers showed they still had a trick or two up their sleeves. With a high-performance, solid-lifter camshaft,…
Click Here to Read the Full Original Article at DragzineDragzine…