Rick it would be very unlikely (read..have yet to see a car I thought was righteous) that the Baltimore plant stamped the VIN by the oil filter for a 1970 Chevelle application. The timeline of the Tonawanda stamping indicates it would most likely be a Van Nuys or Leeds car. The later L78's that I've documented seem to have 1 or 2 weeks in between the Tonawanda stamping and the VIN stamping.

Repectfully,

Greggory Carlson