awag, i also checked the flywheel center hole & hub register on the end of the crank & the gmc is much larger, 2&11/16-3/4". i've been looking at some later model pontiac v8 flywheels on ebay & they have a 2&3/4 center hole & larger bolt patternwith no dowel pin holes. wonder if they'd fit? we're not getting any responses here i wonder this should be moved to the engine forum?
robert
