[QUOTE=C9x]I'm not real familiar with the SBC, but don't you have to be careful in swapping harmonic dampeners due to differing balance/balance weight situations as well as the timing marks can be a mismatch to the timing pointer?
:D Good point, of the factory SBC displacements, only the 400 CID displacements came out with the external balance dampeners and flywheels. All other SBC's came out with internally balanced cranks.
So the 400 SBC came out with the special 8" balancer external balancer only. You will see a large counterweight on the back of the balancer inner hub. It has it's own special part number.
Timing marks will change on both big and small balancers due to emissions. So they can change as the emissions laws got more severe. This was accomplished by either changing the timing tab placement or marks, or changing the timing mark on the balancer inertia ring.
NB the timing marks can also change on old balancers due to the elastomer loosing it's adhesion and walking off or around the hub.
Say C9X, I have my nephews 351W to play with, why did ford come up with a whole heap of different valve diameters and stem lengths for this motor ????
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