For those with more complex engine swaps, such as installing a later-model 302, additional considerations arise. The later roller cam engines require a compatible distributor gear (steel or bronze, never cast iron) and careful attention to harmonic balancer imbalance (50 ounce vs. 28 ounce) . Serpentine belt drives from later engines can often be adapted without body modification, but timing covers and water pump configurations may need attention .
read more..