C3 (1968) L36 Crankshaft Pulley #3921923

[Henry J.]

The 68 AIM indicates that the L36 crankshaft pulley is part number 3921923. There is no indication of a revision from another part number. Just such a pulley is on my car. It is a stamped, semi-gloss black painted, 6 3/4" O.D. pulley.

On page 40 of the fourth edition of M.F. Dobbins' "Vette Vues Fact Book 68-72 Stingray", is photograph of a big block crankshaft pulley. The photo shows a three-spoke, cast and unpainted crankshaft pulley. Although it is not absolutely definitive, the caption suggests that all 68 big blocks were fitted with this cast pulley. [My other references suggest that this cast pulley may be part number 3863108.]

Is anyone able to offer an explanation?

If I'm right about the 3863108 part number, does anyone know whether there are differences in the physical dimensions between the two pulleys?

Thank you very much.

[Joe L.]

Re: C3 (1968) L36 Crankshaft Pulley #3921923

Henry-----

From 1965 thru 1967 the cast iron GM #3863108 was the only crankshaft pulley used for all Corvette big blocks. However, in 1968, things changed a bit. For 1968, the GM #3921923 stamped steel crankshaft pulley came into use for some big blocks. The L-36 was one of the them. So, the 3921923 is correct for your application. Actually, the 3863108 and the 3921923 are functionally interchangeably on most Corvette big block applications, but the 3921923 is still the correct one for your application.

[Henry J.]

Re: C3 (1968) L36 Crankshaft Pulley #3921923

Thank you, Joe. You made my day!