With maturity, short-term goals give way to long-term plans and foresight-at least that's the excuse and rationalization that legitimizes the long and drawn-out history of this Mopar 383 big-block. It was back in the late '80s when the original 383 powerplant was pulled from Musclecar Classics magazine's giveaway Challenger project to make way for a replacement mill. The 383 sat abandoned for several years in a lonely corner of the Hot Rod shop, until then-HOT ROD Editor Jeff Smith determined sufficient time had passed to unceremoniously transfer the tired Mopar to the nearest Dumpster. A reprieve came when then-Feature Editor David Freiburger intervened. The 383 spent the next 12 years in Freiburger's garage, contributing to the impressive collection of potentially useful junk-a hot rodder's foresight at its best.
Freiburger and I have spent endless hours bench-racing what to do with the 383: a big-inch stroker combination; an old-school, tunnel-rammed retro motor; a stock-stroke, high-compression, high-rpm screamer; and so on. When we exhumed the 383 three years ago, we were set on a plan to build a budget high-compression, 7,500-rpm animal, using insanely ported stock iron heads and a good old-fashioned tunnel-ram. The 383 seemed naturally inclined for such an approach with the short 3.375-inch stroke, a relatively large 4.25-inch bore, and a rich history of withstanding abuse during the heyday of '60s muscle.
We would enhance the bore by going straight to 0.060-inch-over, and appease our budget yearnings with the stock forged crank and rods-after all, these factory parts were good enough for Super Stock racers back in the day. For compression we'd need domed pistons, which for a 383 Mopar means custom slugs. We ordered a set from Diamond Racing Pistons, but in doing so fell to the temptations of the custom-piston order sheet. With a literal blank page before us, how could we resist the sultry pleasure of a pair of 0.043-inch compression rings and 3mm oil rings? Of course, at that point lateral gas ports also became a must-have option. So our 11.6cc net dome Diamond pistons were not exactly cheap, but that was ever so easy to rationalize given our high-rpm aspirations and the necessity of custom pistons. After all, the standby L2315F Speed-Pro pistons have ancient-tech 51/464-inch rings, and at best, those flat-tops are good for 9.25:1 compression.
No ordinary machine shop would do for the 383; we needed top-quality work and the personal attention this odd build would require. Beyond the cylinder-bore prep, the stock rods would require resizing with fastidious attention to center-to-center length in order to allow an exact zero-deck machining of the block. Vic Moore and Dave Massey at Precision Speed & Machine had us covered, boring the block, reworking the OEM rods with new ARP bolts, installing the pistons using a press-fit at the pin, and carefully mocking up the assembly and milling the decks for a consistent zero-piston-deck reading. Precision also balanced the stock crank for the 720-gram pistons.
Meanwhile, Freiburger began scouring for a suitable low-deck Mopar tunnel-ram. With online sources such as eBay Motors opening a window to a world of potentially useful junk, the search turned up the needed tunnel-ram and so much more. Mining online sources and local swap meets, Freiburger created a personal subculture dedicated to the accumulation of every low-deck Mopar intake past and present. With that, we had everything required to build our vision of a 383 Mopar except those "insanely ported" OEM iron heads. It would prove to be a roadblock that stalled the 383 project for 18 months, with the only benefit being more time for Freiburger's obsessive pursuit of manifolds. As the stockpile grew, so did the ambition: This would serve as the basis of the most comprehensive low-deck Mopar intake comparison of all time. That ambition redefined the 383 project and ultimately led to its completion.