Chryslers first hemispherical-headed V-8 engines seemed light-years ahead of the competition when introduced for the 51 models, and stayed on the leading edge of performance into the 60s. But by the mid-60s, the new 426 Hemi made the early models obsolete; even Brand X big-blocks became a more favorable choice for many racers. Though the die-hards kept their 354s and 392s running, parts dried up over the years, and today, building an early Hemi can be a difficult and pricey venture.
Some of those hard-core Hemi racers resisted parting with their early iron and refused to shell out exorbitant sums for ancient replacement pieces. One such motorhead is Howard Allen of JMS Racing Engines in Monrovia, California. Howard is a seasoned machinist, but also a veteran of Southern Californias dry lakes and dragstrips. Hes even held a record or two at Bonneville over the years.
These days, most of his working hours are spent as the crankshaft specialist for JMS, but one of his passions is updating and improving vintage engines for performance and reliability. We happened upon a 331ci Chrysler in the process of being refurbished at JMS and had Howard walk us through the updates hes devised for these engines, including tips for 354s and 392s. Most of these changes provide a means for Hemi-builders to create a fully operational engine without relying on expensive replacement parts that may no longer be produced. The accompanying photo captions outline the various tricks Howard and JMS have come up with.