For sure 428SCJ's came with cast iron flywheels since they had the counter balance weight and casting numbers. SCJ's were actually fairly tame with flat tappet std 390GT/428CJ Cams the rev's were not exceeding 6,000 at most. But what about 2x4V 427s? ............... I've seen enough examples of T-Bolt bellhousings to know rev's were a concern. How about lightweight Galaxie's etc
Let's not forget Boss 302's and Boss 351's that I'm pretty sure had factory Rev Limiter's set over 6,000.
A 6,000 rpm flywheel ought to be capable of cutting through a car - did Ford use steel?
