1980 L82 4spd.

[Classiccars]

I know this subject has been discussed a good bit on this site, but I thought I would raise a couple of questions I don't think have been covered.

I have come across the code ZBD for the 1980 Corvette which is supposed to mean the 350ci/230hp engine with a transmission known as "uncertain usage" (at least I think "uncertain usage" refers to the transmission that would come with it). Could it be that "ZBD" is for the handful of cars that actually were an L82 with a 4-spd?

I have never owned a Corvette, and don't know hardly anything about modifying them, but would the 4-spd (MM4?) from an L48 work just fine? Would it be able to handle the extra power of the L82? I believe Chevrolet tried to get the 1980 L82 4-spd emission certified and it failed. But that would imply they had a 4-spd that was compatible with the higher horsepower engine.

Was the 4-spd in a '79 L82 the same transmission used in the L48 in 1980?

Assuming a suitable factory 4-spd (from a '79 L82 or an '80 L48) could be found for a 1980 L82, how difficult is such a swap?

Does anyone know just why the '80 L82 4-spd failed emissions? What specific standards did it not meet (hydrocarbons? carbon monoxide?) and why would it not meet them? If that engine passed with an automatic, why would the transmission have any effect on what was coming out of the tailpipe?

-Jim

 

[JohnZ]

The MM4 transmission was a Borg-Warner Super T-10; same one used in '78-'79 for both base and L-82, no problem handling only the pitiful 220hp of the 1980 L-82. Swap should be a straightforward bolt-in job using stock parts.

 

[Classiccars]

Hey, C'mon, it's 230hp.

Actually, the 1980 L82 is the highest horsepower Corvette from 1975 through 1986.

 

[AGVI]

and it's looks RULE ALL BEOTCHES!

 

[brandywine]

I could be mistaken...but I thought all 1980 L82's came with automatic transmissions.:confused

 

[Classiccars]

For all intents and purposes, the 1980 L82 came only with the automatic. However, there is rumor that a small handful of 4-speeds were initially put in L82's at the beginning of the 1980 model year. Do a search on this site for "1980 L82" and you'll find discussions about these.

From my posts you can see I'm curious as to why these would not pass emissions laws, and specifically why. Also, if I ever were to buy a Corvette someday a 1980 L82 would be very high on the list, if not at the top. But I would consider pulling (and saving) the automatic and dropping in a factory 4-speed manual transmission. So I wanted to know the feasability of this.