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81 Corvette Questions




I don't know a lot about Corvettes (but I will learn). Anyway, I'm looking for a project car, and my Uncle has an '81 Corvette that's literally spent the last six years in his garage doing nothing... he offered to sell it to me a while back and I may take him up on it. So, I have some questions:

The car has the 3-speed auto, is it possible to swap in some kind of manual? If not, what about a whole engine+tranny swap?

The 140 km/h (85 mph) speedo, can that be changed out for something a bit more "normal" as well?

Anything else I should know about that model year?

i think its to much work with frame and adding
cluch and shifter a so expenive just fix it and drive it untill you get what you want
Jaw ~ Welcome to The Corvette Action Center Community ~

The questions you ask are good ones and I feel obligated to be as honest as possible..

Changing from an automatic to a 4-speed is not something one wants to take on for a Sunday afternoon project. You'll need to find all the parts needed to convert the auto to a stick, including the clutch pedal and assy. which means finding the proper brake pedal too, and the linkage associated with them. The console plate will need to be changed and the shifter and associated linkage and cover plate. The ball bracket mounting on the frame and the block and the linkage to the clutch and the pedal.

Also needed will be flywheel, clutch plate, disc, bearing y-yoke parts. Then of course the 4-speed transmission. Also the 81 has computer control to the carb, that also effects the auto-trans torq converter that will need to be disabled.

The (Naders) 85 mph speedo can be swapped out for a 140 mph with out to much problem, but... with the change of the transmission .. there may be some change due to going to the 4-speed. (I'm not sure about the calibration between the auto/4-speed)

Depending on the emissions requirements where you live may decide what you options are for upgrading the engine..

Please check out The L81VetteRegistry for more details on the options and to see what some members that have already changed engines or upgraded their engines.

When it comes to Corvettes.. almost anything is possible if you have the time, desire and the $$$$.. good luck and welcome aboard CACC
Thanks for the reply and the welcome.

Luckily time will never be an issue, because, if I took on a project car I certainly would expect to be an almost never-ending project.

The tranny swap is the most complex wish that I would have for it, and I suppose doing it would really be a factor of if I could find the required parts. I am definately glad to hear that it is not impossible. However, I'll bet finding the parts will prove difficult.

As for the speedo, also glad to hear that it can be changed out. Is it from a specific model/year?


There are many aftermarket Corvette companies out there, a couple that come to mind are "Corvette Central" , "VetteBrakes" I DO NOT endorse either company nor do I work for them.. these are just two that come to mind. There are many more out there too.. Most will have what you are looking for..

Also take a few minutes and check out the Vendors right here on CACC and take a peek at the Portal for more ideas and information.. and of course keep asking questions here.. lot's of experience and help to be found.. ;)

Thanks for everything.

The swap doesn't sound out of the realm of possibility, given I could find someone to do the welding for me, because I don't have any welding skills, and I don't think this would be a good project to learn with...

That is too bad because I am familiar enough with cars to have felt comfortable taking on the project myself (along with friends when needed). I was hoping it would be a simple bolt-in procedure. Oh well.

I think the car itself would keep me busy as it is, given that years of sitting there and quite a bit of neglected maintenance has left some work to be done on it... I think i'd be a hell of a project car, though... so I just might go for it.

Hey, add an "S" and you get "JAWS" (you know, killer shark!!:_rock

Actually, I have rigged up a hydraulic clutch master cylinder in my car.

Based upon that, it makes the swap a little easier. You still have to snag a pedal assembly from a four speed car. I would think you could call around the Corvette recylce yards and pick one up for $100-$300 or so.

You would need the transmission and shifter linkage.

If you plan on taching it up, go ahead and get a good quality steel bell housing.

Finally, you can install a hydraulic release bearing assembly from quarter master. This illiminates welding the linkage to the frame, and makes for a neater cleaner install.

The hydraulic master cylinder is simple. Get a clutch master cylinder for a 1985 One Ton Chevy truck. Get a good quality ball stud from NAPA. Put the master cylinder through the same hole in the firewall that the clutch rod goes (your car will have to be punched out). Measure the throw, cut the rod, and thread it to accept the ball stud. Make a backing plate, and mount it all up. That is it. The resevoir can be mounted almost anywhere.

The hydraulic release bearing takes care of the rest.

I still think you will spend about $2,500 on the swap considering the trans, flywheel, clutch, custom trans mounting bracket, shifter, pedals, hydraulics.

So, why not upgrade to a five or six speed? It is only money.
Items of Interest ? ?


I found something that I think you may find interesting? While checking through my regular sites I saw THIS at the '81 Ebay site (which can also be accessed via the Links page at the L81VetteRegistry).

Happy hunting ;)
A hydraulic clutch would be great..

$2500 is very reasonable... 5 or 6-speed is tempting but I would need to be really careful because I don't want to alter the feel of the gearing too much from what the stock 4-speed car would feel like.

Well I guess I have plenty of time to decide, since it gets too cold in the garage during the winter to work on a car. But, hey, I can use this time to come up with more ideas for the project. :cool

only thing that comes to mind is changing the originality of the car. i've always been one to say make your vette yours, but you have a complete original vette. it's not like you're changing the colour or the wheels or something cosmetic. my .02 worth is that you'd be depreciating the value of the car. from what you said about the car sitting for several years, you're going to be spending most of your $$ on brakes, exhaust, bushings, etc.
been there myself. i bought my '81 out of a barn where it was stored for a few years. good luck which ever way you go.
Re: Mga

You bring up a good point. At this point, I don't really know exactly how I feel about depreciation.

My first focus will indeed be on getting the car itself back up to snuff before attempting anything else. I guess it will be a matter of how happy I am with the car at that point, how much money I have at that point, etc. It is definately good to know that it can be done.

Welcome to the CAC. Looks like a fun project.

You said it is possible to switch out the stock 85 mph speedometer for a 140 mph one, where can I purchase one of these, and how difficult is it to swap?
just a quick look in corvette central i found a 165 mph one.I would think any of themajor vette suppliers would sell them.:w :w

GotMy81@16 said:
You said it is possible to switch out the stock 85 mph speedometer for a 140 mph one, where can I purchase one of these, and how difficult is it to swap?


Take a look at this past thread it has information about where a BUNCH of us got our 140 mph speedo. ;) 140 mph Speedometer

Is it possible that the car may be a rarely equipped L81? Check on this before you decide to tear-into it.

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