I have always been a C1 and C2 guy. From time to time I have considered pulling the trigger on a a C3 but didn't. I am currently thinking about an LS6 coupe with documentation. I know that very few of these cars were produced and that fewer had the M22 trans. I believe the LS6 registry has 58 still accounted for. Why is so little ever said about these cars?

 

IMHO that LS6s are a sleeper right now and could very easily explode in price like the 68/9 L88s have recently. I know for a fact that 3 separate 69L88s have sold for 250K and more recently. If prices go even higher for the best 68/9 L88s, which I believe they will, then collectors will start looking at LS6s as an alternative. Buy the best car that you can afford and hire an expert to look over the car with you. Good luck.

 

I have wondered about that also. Only 188 produced, one year only, high performance. One could maybe argue that the LS-6 corvette lacks the racing history of the L-88.

My biggest concern would be documenting authenticity. I believe it is a relatively easy car to clone. I don't know exactly what went into the engine option LS-6 besides the engine itself. I saw one at a car show once and it had an inline fuel filter with a fuel return line on it and I went.."hmmmmmmmm" because I thought with the Holley carb it shouldn't have the fuel return line. But I couldn't get a definitive answer, even from the NCRS website. Maybe with so few produced they just don't know?

A few years ago, between proteam and Hemmings I counted up 15 of them for sale.

 

If you are looking for a collectable C3 the LS6 would have to be near the top of the list with the L88s and L89s. Almost all LS6s had the M22, about 122 of 188. The remainder had M40.

 

If you could only find a LS6 in a convertible.

 

Sorry, I don't think much of the LS6 with the "low rise" intake and lack of cold air. The L88 is a better big blocak and a 427 will run up to redline way FASTER than a 454 "truck motor" (I don't think much of external balanced motors at all, they don't like high RPMs.) I like my LT-1 and wouldn't trade it for a LS6 Vette because my car corners and is "cheap" to maintain and race. The 435HP L89 aluminum head 68-9 Vette has the same "street mechanical" cam as the LS6 and will outperform that "smog motor" at any drag race. The L88 is in a league of its own. I have ridden in all 3 models of big blocks I have just discussed and the LS6 is in 3rd place on that list of alloy headed big blocks with the L88 head and shoulders above the rest.

 

skyman51,

Good choice if you're looking for something a little different that will probably hold its value over the next few years... Although you may have waited too long to get a really good deal on an LS-6.

Corvette prices generally always move off the top, that is, the cars that bring the highest prices move first. As As Steve (SBR) mentioned, L-88 prices have really taken a huge jump over the last year and I would agree with his comments on current pricing... $200,000 - $250,000 these days is what it takes to buy a quality 1968 or 1969 L-88. As a result of that, prices on the other cars have also seen a nice increase and that includes the LS-6s. Right now, a quality LS-6 coupe is going to be in the $85,000 - $90,000 range while a convertible will see $120,000 - $130,000... These prices being for a correctly restored car with documentation. I had always considered the LS-6 to be a real bargain in past years, but I don't think that statement is true any more.

There probably is very little said about the 1971 LS-6 cars because as you mentioned, there are so few of these cars around. The fact that the LS-6 has (and probably always will) live in the L-88s shadow in Corvette circles also plays a big part. Still, there is information out there if you know where to look and who to talk to... And the 1971 LS-6 is still an excellent car regardless of any comparisons to the L-88 cars. The current LS-6 survey has around 66 cars if I'm not mistaken.

Steve,

I don’t think I would call it a sleeper any more… Prices have already moved to a point where it is hard to consider it a bargain.

By the way, I have looked in my files for the header information that you requested and have not been able to locate it to this point (I’ve gone through everything I have in storage). I know I have it… If it should turn up in the future, I’ll see that you get copies of what I have.

MJ,

Yes, documenting a real LS-6 can be a bit difficult, but there are still a few items that make “cloning” an LS-6 car a tough proposition. The L-89 is, without a doubt the easiest of the three cars being discussed to create… The LS-6 and L-88 are quite a bit harder to fake.

The issue with the fuel pump was discussed in a thread in this forum several years ago... Not sure if you remember it. While the LS-6 did use a fuel pump with a fuel return line, an inline filter was not used. I believe that the current NCRS judging manual also holds with this assessment.

mstanton,

I would definitely agree with you that among the 1968-1982 Corvettes, the L-88, LS-6, and L-89 are definitely near the top of the list when it comes to value.

The transmission issue is somewhat interesting with the regard to the LS-6. The standard transmission installed when the LS-6 was ordered was the M-21 close ratio four speed manual (which was available optionally on other 1971 Corvettes). The two optional transmissions were the M-22 heavy duty four speed manual as well as a heavy duty version of the M-40 automatic. Both of the manual transmissions used a dual disc clutch as well. The survey information would lead you to believe that the split was actually pretty even between the three transmissions, but without more complete production information from GM, it is difficult to say.

Solid LT1,

The intake manifold for the LS-6 is probably the one of the few negative points on the car… And considering the fuel distribution issues inherent with the tripower manifold, I’d call it pretty much a wash. I’ve owned all of the cars that you mentioned with the exception of the L-88 (and I’ve driven a few of those) and the LS-6 is probably the best of the bunch when it comes to actually driving them. The LT-1 is great and I’ve always been a huge fan of that engine (I’ve had four 1970s and one 1971), but from the standpoint of acceleration, it’s not in the same league as the other engines that you mentioned… Close, but not quite. The handling is marginally better than the big block cars, but for what you give up to the big blocks in power, I’m not sure that it’s worth it. To each his own though…

The L-88 was a great racecar in its day and still an incredible performer even today, but it has its shortcomings. The engine is choked by the factory exhaust… The M-22 cars lacked a fan shroud for low speed cooling… Vacuum to operate the power brakes is non-existent below about 3000 rpm. I would agree with you that it is in a league of its own as an important part of Corvette history and still pretty darn impressive in a drag race, but it’s also about the worst of the group to actually drive on the street.

The L-89 is a great street engine in its own right and the “cool” factor is definitely there with the tripower, but the extra torque provided by the additional displacement of the LS-6 is a big advantage when you’re trying to get a heavy (3,500+ pounds) Corvette off the line. The high rpm issue you mentioned is somewhat irrelevant to our discussion since the “143” camshaft used in both engines falls off sharply in the power department after 6000 rpm… There’s just no need to push it past the factory redline with the stock camshaft. The internal/external balance issue isn’t very relevant at the rpm ranges these engines operate in either. The lower compression actually works in favor of the LS-6 as it is a better fit for the factory exhaust system too… Not to mention the 1969 version of the L-89 only used a 2” diameter exhaust. Finding fuel for that 11 to 1 compression L-89 isn't easy these days either.

From the standpoint of actually driving these cars on the street today, the LS-6 is definitely first. For collectibility, most definitely the L-88 with the LS-6 edging out the L-89 for second.

Regards,

 

skyman51,

Good choice if you're looking for something a little different that will probably hold its value over the next few years... Although you may have waited too long to get a really good deal on an LS-6.

Corvette prices generally always move off the top, that is, the cars that bring the highest prices move first. As As Steve (SBR) mentioned, L-88 prices have really taken a huge jump over the last year and I would agree with his comments on current pricing... $200,000 - $250,000 these days is what it takes to buy a quality 1968 or 1969 L-88. As a result of that, prices on the other cars have also seen a nice increase and that includes the LS-6s. Right now, a quality LS-6 coupe is going to be in the $85,000 - $90,000 range while a convertible will see $120,000 - $130,000... These prices being for a correctly restored car with documentation. I had always considered the LS-6 to be a real bargain in past years, but I don't think that statement is true any more.

There probably is very little said about the 1971 LS-6 cars because as you mentioned, there are so few of these cars around. The fact that the LS-6 has (and probably always will) live in the L-88s shadow in Corvette circles also plays a big part. Still, there is information out there if you know where to look and who to talk to... And the 1971 LS-6 is still an excellent car regardless of any comparisons to the L-88 cars. The current LS-6 survey has around 66 cars if I'm not mistaken.

Steve,

I don’t think I would call it a sleeper any more… Prices have already moved to a point where it is hard to consider it a bargain.

By the way, I have looked in my files for the header information that you requested and have not been able to locate it to this point (I’ve gone through everything I have in storage). I know I have it… If it should turn up in the future, I’ll see that you get copies of what I have.

MJ,

Yes, documenting a real LS-6 can be a bit difficult, but there are still a few items that make “cloning” an LS-6 car a tough proposition. The L-89 is, without a doubt the easiest of the three cars being discussed to create… The LS-6 and L-88 are quite a bit harder to fake.

The issue with the fuel pump was discussed in a thread in this forum several years ago... Not sure if you remember it. While the LS-6 did use a fuel pump with a fuel return line, an inline filter was not used. I believe that the current NCRS judging manual also holds with this assessment.

mstanton,

I would definitely agree with you that among the 1968-1982 Corvettes, the L-88, LS-6, and L-89 are definitely near the top of the list when it comes to value.

The transmission issue is somewhat interesting with the regard to the LS-6. The standard transmission installed when the LS-6 was ordered was the M-21 close ratio four speed manual (which was available optionally on other 1971 Corvettes). The two optional transmissions were the M-22 heavy duty four speed manual as well as a heavy duty version of the M-40 automatic. Both of the manual transmissions used a dual disc clutch as well. The survey information would lead you to believe that the split was actually pretty even between the three transmissions, but without more complete production information from GM, it is difficult to say.

Solid LT1,

The intake manifold for the LS-6 is probably the one of the few negative points on the car… And considering the fuel distribution issues inherent with the tripower manifold, I’d call it pretty much a wash. I’ve owned all of the cars that you mentioned with the exception of the L-88 (and I’ve driven a few of those) and the LS-6 is probably the best of the bunch when it comes to actually driving them. The LT-1 is great and I’ve always been a huge fan of that engine (I’ve had four 1970s and one 1971), but from the standpoint of acceleration, it’s not in the same league as the other engines that you mentioned… Close, but not quite. The handling is marginally better than the big block cars, but for what you give up to the big blocks in power, I’m not sure that it’s worth it. To each his own though…

The L-88 was a great racecar in its day and still an incredible performer even today, but it has its shortcomings. The engine is choked by the factory exhaust… The M-22 cars lacked a fan shroud for low speed cooling… Vacuum to operate the power brakes is non-existent below about 3000 rpm. I would agree with you that it is in a league of its own as an important part of Corvette history and still pretty darn impressive in a drag race, but it’s also about the worst of the group to actually drive on the street.

The L-89 is a great street engine in its own right and the “cool” factor is definitely there with the tripower, but the extra torque provided by the additional displacement of the LS-6 is a big advantage when you’re trying to get a heavy (3,500+ pounds) Corvette off the line. The high rpm issue you mentioned is somewhat irrelevant to our discussion since the “143” camshaft used in both engines falls off sharply in the power department after 6000 rpm… There’s just no need to push it past the factory redline with the stock camshaft. The internal/external balance issue isn’t very relevant at the rpm ranges these engines operate in either. The lower compression actually works in favor of the LS-6 as it is a better fit for the factory exhaust system too… Not to mention the 1969 version of the L-89 only used a 2” diameter exhaust. Finding fuel for that 11 to 1 compression L-89 isn't easy these days either.

From the standpoint of actually driving these cars on the street today, the LS-6 is definitely first. For collectibility, most definitely the L-88 with the LS-6 edging out the L-89 for second.

Regards,