ScottNM Posted May 31, 2011 Share Posted May 31, 2011 I have heard it rumored that there may possibly be a few L-6 454 units. How would one know if the L-6 unit was originally put in the car besides a build sheet and would the build sheet specify L-6 Quote Link to comment Share on other sites More sharing options...
Canuck Posted May 31, 2011 Share Posted May 31, 2011 This question comes up periodically. None of us here at the FGMCC have seen proof that a monte rolled out of the factory with the LS6 engine. There are some rumours around but no proof. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted May 31, 2011 Author Share Posted May 31, 2011 The build sheet would say L6 would it not? I have a fellow who has a SS. He has not found build sheet but has never dropped the tank. It has the protector plates on the rear suspension. He is calling me with the engine# soon which matches the vin. He worked for GM and bought the car from original owner in 76. He claims is was the 454/450hp engine. He says you had to special order one to get it. He said it came with a 950 cfm quad carb. What do you think? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted May 31, 2011 Share Posted May 31, 2011 sure would be cool if is true Quote Link to comment Share on other sites More sharing options...
Canuck Posted May 31, 2011 Share Posted May 31, 2011 LS-6, not L6, would be on the build sheet. Â Maybe some of the big block guys can chime in on wheather there are numbers stamped on the block that indicate an LS6. Â If I was him, I'd be looking for a build sheet on the gas tank or in/under the seats among other places. We have seen a case before where a person changed the "5" in LS-5 to a "6" on the build sheet but it was clear when you looked closely that it was altered. Â This type of story pops up from time to time but proof never materializes. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted May 31, 2011 Share Posted May 31, 2011 the engine code for a 1970 LS6 is CRR or CRS with a TH400 Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted May 31, 2011 Share Posted May 31, 2011 sure would be cool if is true the suspense is killing me.. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted May 31, 2011 Author Share Posted May 31, 2011 As soon as I get some #s I will post them. It was raining where he was and I told him to get it when convenient. I would love to drive there but its to logn and if it does not pan out, then I wasted time. I did notice ls-6 (some) had a 982cfm carb. He is claiming it had one but he sold it. Anyway this story is not concluded yet. I will keep you posted. Quote Link to comment Share on other sites More sharing options...
overdrive Posted May 31, 2011 Share Posted May 31, 2011 From our Tech Info section:   All SS Monte Carlos in '70 and '71 were 454s and all 454s in '70 and '71 were SS cars. So, if there is a numbers matching 454 in the car, that is a good indication it is a real SS. The VIN should match the serial number on the engine. The engine serial number is usually found on the machined surface of the block just forward of the right cylinder head. It may also be found on a pad on hte side of the block near the oil filter. The serial number will start with "CRN" for '70 and "CPD" for '71.  No SS’s have:  LS6- 450 hp 454 – please prove me wrong, until then…  There's more info here  CPD and CRN both indicate a LS-5, 360 HP.  Quote: He claims it was the 454/450hp engine. He says you had to special order one to get it.  If he has it, I want it.  Dan Quote Link to comment Share on other sites More sharing options...
LS5 Posted May 31, 2011 Share Posted May 31, 2011 From my neck of the woods, on the 70 Chevelle SS. The LS-6 had different heads and intake and carb from the LS-5, also NO LS-6 Chevelle ever came with AC but did have Smog like the LS-5, it is also Denoted on the Build Sheet as a LS-6 454-450HP and yes on those block codes mentioned except it was CRT not CRS sort of, CRS was 450HP but that code was for the Aluminum headed 454 and only 18 pairs were sold back in 1970 so if you have a pair of those you have a small fortune sitting there.... The 1970 Corvette had the LS-6 as well. I also know that Tach & gauges were an option but on "The King of The Hill " cars as they called them the LS-6 came standard with Tach and Gauges. The Cowl Induction Hood cars had the air element that sealed to the hood via rubber ring and the Fresh air hood (ducted but no flapper) had a Double Snorkle air cleaner on them.Redline on the Tach was different too and 373 or 411 gears in the rear,and I believe the rest was optional on the chevelle wise unless Nate or Crazy Dave can correct me....??? Darren. Darren. Quote Link to comment Share on other sites More sharing options...
LS5 Posted May 31, 2011 Share Posted May 31, 2011 Do these help....?????  1970 Engine ID Codes Engine Transmission Carb Code Size HP Auto Manual 1 bbl 2 bbl 4 bbl CCK 250 155 TH-350 1bbl CCL 250 155 Manual 1bbl CCM 250 155 PGlide 1bbl CKO 396 375 Manual 4bbl CKP 396 375 Alum TH-400 4bbl CKQ 396 375 Manual 4bbl CKR 396/400 330 Manual 4bbl CKS 396/400 330 Manual 4bbl CKT 396 375 Manual 4bbl CKU 396 375 Manual 4bbl CNC 307 200 Manual 2bbl CND 307 200 Manual 2bbl CNE 307 200 PGlide 2bbl CNF 307 200 TH-350 2bbl CNI 350 250 Manual 2bbl CNJ 350 300 Manual 4bbl CNK 350 300 PGlide 4bbl CNM 350 250 PGlide 2bbl CRE 350 300 TH-350 4bbl CRN 454 360 Manual 4bbl CRQ 454 360 TH-400 4bbl CRR 454 450 TH-400 4bbl CRS 454 450 Alum TH-400 4bbl CRT 454 360 Manual 4bbl CRV 454 450 Manual 4bbl CTW 396 350 TH-400 4bbl CTX 396 350 Manual 4bbl CTY 396 375 TH-400 4bbl CTZ 396 350 Manual 4bbl  Darren. Quote Link to comment Share on other sites More sharing options...
Dans '70 Z20 Posted May 31, 2011 Share Posted May 31, 2011 Keep in mind the three letter code is also specific to the Monte Carlo. The codes listed above are for all Chevy's. Â I have an original 70 SS454 with docs and my engine code is "CRN" and based on the list I should have a manual but have a Turbo 400. Â Not a perfect list just to let people know. I believe the info in our tech section reviews the possible "letter codes" on a Monte with certain engine. Quote Link to comment Share on other sites More sharing options...
LS5 Posted June 1, 2011 Share Posted June 1, 2011 I thought the monte carlo was a chevy and the codes are not specific so I thought..?? The list was from Team chevelle and those codes are for corvettes and impalas too. The CRN is the code from your block that says that BLOCK is a manual block not an automatic block.And with GM doing so many goofy things back in the day you could have a rare monte that is denoted as a automatic yet the factory chucked in a manual coded block, just ask around there are lots...hence the guessing on weather or not there is an LS-6 monte carlo that may have gotten the wrong engine... Didnt mean to offend anyone with a free block code list that wasnt claimed to be perfect... Quote Link to comment Share on other sites More sharing options...
RichG Posted June 1, 2011 Share Posted June 1, 2011 Gotta throw my 2 cents here. Highly unlikely that the factory would have "accidently" installed an LS-6 in place of an LS-5. LS-6 had different fuel lines etc from an LS-5. When you look at all the different assembly line groups that would have been affected by it, it seems unlikely that several inspectors would overlook such a mistake. A single item could make it, like a steering wheel but too many auxillary parts are not the same.Granted freak things DID happen but a mistake engine or trans is highly unlikely. In the 40 years that the cars have been around, to date, not 1 verified LS-6 has been found. There have been many "my next door neighbor's plumbers brother had one" but ZERO real documented ones. Just my opinion, I could be wrong. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted June 1, 2011 Share Posted June 1, 2011 the same goes for a 4 speed SS monte, the closest thing to that is a 1971, 402/4 spd, bench seat that has the SS rear trim, we know at least one of these excist Quote Link to comment Share on other sites More sharing options...
LS5 Posted June 1, 2011 Share Posted June 1, 2011 So how does that work on Dans car..? It is denoted as what I think from other sources like team chevelle and Dan Carr that his code is a 4spd block code yet his car has a th400 from factory and he has a build sheet too, also all 4 cars used CRQ as an LS-5 code. Both monte and chevelle as 360hp in 1970 and the vette and impala at the 390hp all CRQ?? Quote Link to comment Share on other sites More sharing options...
ScottNM Posted June 1, 2011 Author Share Posted June 1, 2011 OK guys, I need your help. Here is the engine code TO424CRW This car is a 72 so I quess it could not be a SS? The next question is could you get a 454 in a 72 and did the suspension is such correspond? If this car is a true 72 454, is it not the value of a 70-71 SS? Thanks Quote Link to comment Share on other sites More sharing options...
LS5 Posted June 1, 2011 Share Posted June 1, 2011 Hey scott here is my 2 cents worth which may or may not be right but someone will let you know if it's right.. CRW 454 270hp TH-400 4bbl This would be a "W" Code Monte Carlo...I believe the W Code replaced the SS as it was not offered in 1972 just 70-71. as far as its value compared to the other two years I will leave that to the other guys...But I am guessing no...., but its still worth something to the right buyer.... Darren. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted June 1, 2011 Author Share Posted June 1, 2011 I believe your right. The 5th digit is W in the vin. It is a matching #s 1972 454 that is not a true SS. Well, it is in excellent condition with paint and the interior is original in great condition. 400th tranny, not sure about the rear. It has been bored over.30 does 12500 seem high? 90k second owner and he has owned it since 76. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted June 1, 2011 Author Share Posted June 1, 2011 One thing I do not have is the engine casting # So here is some data I found  3963512 1969-72 454 2/4 345, 360, 365, 390, 425, 450, Chevelle, Corvette, Monte Carlo  Correct me if I am wrong but it shows that IF the casting # is 3963512 it will be a minimum of a 345hp unit or above, even in a 72. Quote Link to comment Share on other sites More sharing options...
RichG Posted June 1, 2011 Share Posted June 1, 2011 According to the 1972 AMA data that Chevrolet provided, on page 3 of the General section, it lists the engine code for a 1972 270 HP 454 as "CPD" There is no "CRW" engine code listed for a 1972 Monte according to the AMA Booklet. There is a link to all 3 year booklets posted under the Restorers Forum from 04/25/11. These really should have a sticky at the top of the Restorer Forum, they are chock full of answers to common questions. There is a Camaro site with engine codes that does list a CRW but I would trust the data that Chevy provided. It would be interesting to see build sheets from 72 454 cars to see how they are coded. Quote Link to comment Share on other sites More sharing options...
RichG Posted June 1, 2011 Share Posted June 1, 2011 Keep in mind the three letter code is also specific to the Monte Carlo. The codes listed above are for all Chevy's. I have an original 70 SS454 with docs and my engine code is "CRN" and based on the list I should have a manual but have a Turbo 400.  Not a perfect list just to let people know. I believe the info in our tech section reviews the possible "letter codes" on a Monte with certain engine.  Dan, The AMA booklet for 1970 Monte lists CRN as a Optional Engine, 3 speed 4bbl Carb. We know that a 3 speed manual was only available with the 350 2-bbl and that 454 required an Automatic. They must have left the "Auto" part off of the description. They also list CRQ as a valid 1970 454 code with Automatic. Quote Link to comment Share on other sites More sharing options...
Shadow Gray SS Posted June 1, 2011 Share Posted June 1, 2011 mine is CRN on block & buildsheet. Â The resto pack I got from GM says CRN for '70 ss monte... Quote Link to comment Share on other sites More sharing options...
Canuck Posted June 1, 2011 Share Posted June 1, 2011 OK guys, I need your help. Here is the engine code TO424CRW This car is a 72 so I quess it could not be a SS? The next question is could you get a 454 in a 72 and did the suspension is such correspond? If this car is a true 72 454, is it not the value of a 70-71 SS? Thanks  These stories always seem to end up this way. Someone says they have a one of a kind ultra rare car and it turns out to be a regular production car. Don't get me wrong, a 72 454 Monte is a great car but not the "special order" car that was thought to be.  Only 1,268 72 454 Montes made so it's not common. There are people who seek these out but they don't seem to have as much value as a 70/71 SS. If the car is a 72 Custom with a 454, that would give it even further value. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted June 1, 2011 Share Posted June 1, 2011 the '72 454 is rated at 270 hp. They came with a TH400 and a 12 bolt rear end. Should also have a rear swaybar and boxed lower rear control arms. The "W" car as they are known was not intended as a replacement for the SS of 70/71, there was no attempt at an SS car in '72 (W cars were not available in California). That said everything that was in the SS package still had a box you could check in '72 so it was possible to have a '72 with the exact options as the earlier SS cars. Â Of the 3 Gen I years the "W" cars are the rarest but valuewise probably rank third in 454 cars... Quote Link to comment Share on other sites More sharing options...
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