66 L79 with 3.70 gear

[Chris H.]

I'm looking at a 66 L79 with a March build date. I'm confused as the original window sticker says it has an "FA" (3.70) gear. But the protecto plate and the diff stamp says "AO......". Shouldn't the diff have an "FA" stamp on it?

Thanks, Chris

[Wayne M.]

Re: 66 L79 with 3.70 gear

I'm looking at a 66 L79 with a March build date. I'm confused as the original window sticker says it has an "FA" (3.70) gear. But the protecto plate and the diff stamp says "AO......". Shouldn't the diff have an "FA" stamp on it ? ....

This is one case where the ECL code on the build sheet/window sticker just HAPPENS to use the same code for 3.70 small block as the differential stamping for the big block. Your diff stamping is correct if 'AO'.

The ECL code for a big block 3.70 is 'NA', and the diff is stamped 'FA'

[John H.]

Re: 66 L79 with 3.70 gear

I'm looking at a 66 L79 with a March build date. I'm confused as the original window sticker says it has an "FA" (3.70) gear.

Chris -

The "FA" on the sticker (2G81FA) is an ECL code, not a Broadcast Code; the "AO" stamp on the diff housing is the Broadcast Code, which is duplicated on the P-O-P. The "FA" is only seen on the window sticker, Corvette Order, and Car Shipper; it was used as a discriminator in the Engineering Releasing System.

[Chris H.]

Re: 66 L79 with 3.70 gear

Thanks Gentlemen. I was confused because my 65 396 car had the "FA" stamped right on the differential.

Thanks, Chris