1968 L/89

[OLD IRON]

Does anyone know what month the first L/89's were made?

[KurtS]

I've seen nothing that indicated they weren't available at the start of production.

[Jerry@CHP]

They were available at the beginning of 1968 production.  As a matter of fact, find the May 1968 issue of Super Street Cars.  They did an awesome article on one of the first '68 L89's to arrive in the NY area.  Has the early bumble bee SS stripe meaning it was built Sept-Dec 1967.  Deliever to Oak Hill Chevrolet, Eastchester, NY.

One of the best articles out there with many photos.

Jerry 

[OLD IRON]

Thanks for the info' Kurt & Jerry.

Were the L/89's assembled at both plants?

Joe.

[1968 Z28]

All big block engines were assembled at the Tonawanda (NY) engine plant.

[KurtS]

And both assembly plants built L89 cars.

[L78racer]

Did the L89 use a different piston than the iron head?

[bertfam]

I'm assuming you mean different from the L78, and the answer would be no. Only difference between the L78 and L89 was the addition of the aluminum heads.

Ed

[L78racer]

Thanks. I'm assuming the aluminum head also used a composite gasket. Wouldn't you take a compression hit by the thicker gasket?

[bertfam]

Yes, a different gasket was used. Cast iron L78 heads used the 3863199 gasket while the aluminum L89 heads used the 3921940 gasket. The "compressed thickness" probably had minimal effect, if any, on the compression ratio.

Ed