I purchased this 71 convertible 4 speed last summer from a fellow in PA. It does not have power windows, steering or air or brakes. It has a cut off switch (battery) located in the middle compartment of the back storage area. Would anyone know if this was "stock" or could it be one of the race cars sold in that year. It has a 454 in it with a M-20 tranny, the fellow said motor had been replaced and rebuilt by the previous owner. The tag on the 4 speed plate says 425 hp? I cannot find the metal build tag anywhere, did the stock 71 have a metal tag attached to the engine side firewall??
thanks for any help,
Ron

If the horsepower plate next to the shifter is original to the car, it came equipped with a 454 LS6 engine, 425 horsepower with aluminum heads. An original engine block would have the suffix CPW stamped on it by the VIN. It would also have a block casting number of 3963512, and the heads should have casting number of 3994026. This is all from the Corvette Black Book.

Also, according to the Black Book, only 188 LS6 Vettes were assembled for the '71 model year, and apparently the M20 wide ratio was not available, it should have either an M21 or M22 close ratio tranny installed.

Without documentation, there's really no way of knowing if your car was an original race vehicle. It sounds a bit doubtful as '71 was the first year GM engines had to work with low lead gasoline and horsepower ratings began to be reduced somewhat. That's not saying someone didn't order it to use for racing and simply spec'd it out that way. The battery cut-off could easily be an aftermarket installed after it was delivered.

As far as a metal tag, I don't know the answer to that.

Thanks Gunslinger, Yea I know. The engine is stamped with a fx something meaning I think it is a Marine Engine which means it should all be forged stuff. The tranny is not stock and it is a M-20 by the numbers. The fellow said it was replaced & rebuilt. That's all he knew. I agree, it is probaly not one of the ZR-2's . Thanks Ron

If it was an original '71 LS6 454/425, it would be worth $60K+ if in reasonable condition. No matter how unlikely, I'd investigate all the possibilities since it could be a windfall.

Thanks Joe, I'm checking out all the possibilities. You never know.
thanks
Ron

Well today is Saturday and I pulled the gas tank, looked behine the dash and checked all the frame rails and no build sheet. Oh well, I'm not too lucky. I found out there were only 17 Convertible LS-6's ran for 71. I doubt if mine is one of them. I have a good, solid 71 Black Convertible and that's ok by me.
thanks for all the suggestions.
Ron

dolamiti:

Ron; How did you determine there were 17 LS6 convertibles?

I own a '71 LS6 coupe, I've been trying to research the engine/trans breakdown, as well as coupe/convertible breakdown statistics without much success.

As far I know, we are not even sure of the actual production numbers yet. According to the Tonawanda engine facility, they show that 212 engines were assembled and coded for the LS6 application. According to M. F. Dobbins, in his Stingray Fact Book, he states there were 196 LS6 'vettes produced for the '71 model year.

If we are to believe Antonicks Corvette Black book, he states a production of 200 LS6 cars, with 12 being ordered with the ZR2 option, leaving 188 LS6 cars.

The late NCRS Team leader Hans Norberg wrote an initial survey article about the elusive LS6 cars. He implies that there were approximately 34 or 36 engines coded from Tonawanda for application as THM 400 and approximately 162 to 165 engines coded for M22/M21 applications. He further stated that approximately 10% engines built for warranty purposes.

The Black book states that there were 12 ZR2's and 8 ZR1's. If you start out with the only known hard fact of 212 coded engines and deduct 10% production for warranty purposes, you start with a figure of 191 cars (not that far off from either the 196 or 188 figures previously stated by 2 different sources) take from that the ZR series of 20 cars, leaving 171 normal LS6 optioned cars. Black book says 130 M22's, I have not heard of any LT1's ordered with M22 trans, OTHER than the ZR1's.
So further reduce the M22's to 110 units for LS6's, leaving approximately 71 cars either equiped with M21 or THM 400. Using the suggested figure of 35 units for THM 400 equiped cars, that leaves approximately 36 units for M21 applications. I personally have seen 1 M21 equiped LS6, verified by the original POP pamphlet.
NCRS, by the way has on it's survey list, has located and verified at least 69 LS6 cars, I saw the list back in 2001. This is approximately 1/3rd of production. I however have not seen any documentation to show body configuration breakdowns. I am assuming since there is a 2 to 1 ratio of coupes to convertibles, that is how you arrived at the 17 unit figure.