1970 lt-1 motor
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Joined: May 2004
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From: Austin TX
1970 lt-1 motor
I have a 1970 lt-1 motor that came with a '69 I bought that I'm now pondering what to do with. I was told that the previous owner used to race this car so I guess he bought the lt-1 motor over the counter because it doesn't have a vin stamped on the front pad, it only reads T 07 27 CTR. Is this normal? I thought the "replacement" engines had a special stamping? Maybe I should start looking for a '70 LT-1 w/o the original motor... 
I'm considering having it rebuilt to factory specs but it doesn't seem like GM sells rebuild kits for this motor anymore, anyone know where I can get a rebuild kit?
Thanks.
I'm considering having it rebuilt to factory specs but it doesn't seem like GM sells rebuild kits for this motor anymore, anyone know where I can get a rebuild kit?
Thanks.
Melting Slicks
Joined: Jan 2006
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From: Nashville TN
I dont think the motor is original to the car and I dont think its a LT-1. Your suffix code reads as follows:
CTR 75 400 Impala 175hp LT-4 T-H 400 4-Brl
CTR 78 305 Buick 145hp LG-3 TH 350 2-Brl Century, Regal
I also think Corvettes are the only ones with vin's stamped on the block (not 100% sure). Can anyone advise on this?
CTR 75 400 Impala 175hp LT-4 T-H 400 4-Brl
CTR 78 305 Buick 145hp LG-3 TH 350 2-Brl Century, Regal
I also think Corvettes are the only ones with vin's stamped on the block (not 100% sure). Can anyone advise on this?
Race Director
Joined: Dec 1999
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From: Forked River NJ
That does not sound like a LT1 motor. It might have been built with some LT1 parts but it is not a true LT1 motor. Build the motor how you want it. The LT1 is a good motor but there is better internals available today with better cams and heads.
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From: Austin TX
Looking at this site: http://www.nastyz28.com/sbchevy/spcode3.html I see the CTR code referenced for a couple of different blocks, I'm curious why you say it doesn't sound like a lt-1 motor? While it doesn't prove anything it had a corvette distrubutor and an '69 z-28 intake. Where would I find the numbers on the heads?
Melting Slicks
Joined: Jan 2006
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From: Nashville TN
I stand corrected, good for you and glad it seems to be what you wanted. NO vin stamp however would puzzle me and if it were a corvette block I would think it would be on there. Other year CTR blocks didnt have the vin.
My first source didnt have CTR for any years other than the two I listed. I checked another source and its there.
no Vin stamp makes me wonder.
Head numbers are stamped inside the heads themselves. Take the valve covers off and they are on top.
Whats the block casting number?
Replacement blocks and over the counter blocks were stamped CE before the number also if I recall, not sure and someone please correct me.
My first source didnt have CTR for any years other than the two I listed. I checked another source and its there.
no Vin stamp makes me wonder.
Head numbers are stamped inside the heads themselves. Take the valve covers off and they are on top.
Whats the block casting number?
Replacement blocks and over the counter blocks were stamped CE before the number also if I recall, not sure and someone please correct me.
Race Director
Joined: Dec 1999
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From: Forked River NJ
I don't have my books here with me so I can't check the numbers. The heads are cast in numbers not stamped in numbers. They are under the valve covers. No pad stamping could mean the block may have been decked at some time also. Post some of the casting numbers of the block and heads and we can help you out.
The motor that was in my car was a 78 passenger car motor when I got it. It had the correct dist, alternater strarter and a few other things. They just switched all that stuff over to a crappy motor.
The motor that was in my car was a 78 passenger car motor when I got it. It had the correct dist, alternater strarter and a few other things. They just switched all that stuff over to a crappy motor.
Last edited by Gordonm; Mar 22, 2006 at 11:06 PM.
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From: Austin TX
The numbers on the heads are 3927186 and 3991492. The block casting number is 3970010. The engine is VERY dirty and sitting in the back of my dark garage so no guarantees on the numbers.... at least not until the weekend.
Thanks for all the info so far!
Thanks for all the info so far!
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Melting Slicks
Joined: Jan 2006
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From: Nashville TN
3927186
302/327/350 68-72 1.94/1.50 2.02/1.60 64cc Doubble humps Bolt holes
3991492
327/350 68-73 1.94/1.50 2.02/1.60 64cc Angle plug
This guy has the same two heads you have, I think they said one was a replacement. Maybe you two can swap one to come up with a matched pair?
http://forums.corvetteforum.com/show...7&forum_id=119
Sorry about the stamping vs casting in the earlier post. Im a technical dork when it comes to correct terms.
Dont hold me to the numbers ive been wrong already once in this thread hahaha
302/327/350 68-72 1.94/1.50 2.02/1.60 64cc Doubble humps Bolt holes
3991492
327/350 68-73 1.94/1.50 2.02/1.60 64cc Angle plug
This guy has the same two heads you have, I think they said one was a replacement. Maybe you two can swap one to come up with a matched pair?
http://forums.corvetteforum.com/show...7&forum_id=119
Sorry about the stamping vs casting in the earlier post. Im a technical dork when it comes to correct terms.
Dont hold me to the numbers ive been wrong already once in this thread hahaha
Melting Slicks
Joined: Dec 2002
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From: Belmont Michigan
The 186 would be correct, but the 492 would be off of a '73 Camaro, I believe. Look for date codes on the heads- a letter followed by 3 numbers. Look also for the casting date on the block- behind the pass. side head on the block, right above where the bellhousing mates to it.
Rich
Rich
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From: Yuma Az
Originally Posted by MidShark
The 186 would be correct, but the 492 would be off of a '73 Camaro, I believe. Look for date codes on the heads- a letter followed by 3 numbers. Look also for the casting date on the block- behind the pass. side head on the block, right above where the bellhousing mates to it.
Rich
Rich
The Chevrolet by the numbers states that the 3991492 head was a replacement head for the 1970. These heads came with screw-in rocker arm studs and pushrod guide plates. Does your 492 heads have the screw in studs and guide plates?
Melting Slicks
Joined: Jan 2006
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From: Nashville TN
I think the true lt-1 motors were 4 bolt main motors and the other dates that used the motor were 2 bolt. You could pull the pan and check. Again im not 100% sure but there will be someone who is sure and post right behind me (we hope).
Safety Car
Joined: May 2005
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From: Jennings LA
Originally Posted by LittleJake
I also think Corvettes are the only ones with vin's stamped on the block (not 100% sure). Can anyone advise on this?
Melting Slicks
Joined: Dec 2002
Posts: 2,390
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From: Belmont Michigan
Originally Posted by gator79
is this true? mine is not matching numbers but it does have a vin on it.
saltyfrog- if you get to the point of pulling the pan, look for a dab of "pink" on each connecting rod, along with 3/8" rod bolts, and of course the 4-bolt mains. This would verify LT-1 internals.
What does not add up, though, in my mind, is the "T" on the stamped pad. I was under the impression that all small block Vette engines were assembled in Flint, and should have a "V" preceding the date code. The casting date on the block is indeed where I described, in much smaller characters than the casting number. That date would be very telling. A serial number might also be stamped above where the oil filter screws on, on the driver's side. Check it all out.
Rich
Drifting
Joined: Sep 1999
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Originally Posted by MidShark
No, other Chevrolet cars usually had some #s from the vin stamped on the pad as well.
saltyfrog- if you get to the point of pulling the pan, look for a dab of "pink" on each connecting rod, along with 3/8" rod bolts, and of course the 4-bolt mains. This would verify LT-1 internals.
What does not add up, though, in my mind, is the "T" on the stamped pad. I was under the impression that all small block Vette engines were assembled in Flint, and should have a "V" preceding the date code. The casting date on the block is indeed where I described, in much smaller characters than the casting number. That date would be very telling. A serial number might also be stamped above where the oil filter screws on, on the driver's side. Check it all out.
Rich
saltyfrog- if you get to the point of pulling the pan, look for a dab of "pink" on each connecting rod, along with 3/8" rod bolts, and of course the 4-bolt mains. This would verify LT-1 internals.
What does not add up, though, in my mind, is the "T" on the stamped pad. I was under the impression that all small block Vette engines were assembled in Flint, and should have a "V" preceding the date code. The casting date on the block is indeed where I described, in much smaller characters than the casting number. That date would be very telling. A serial number might also be stamped above where the oil filter screws on, on the driver's side. Check it all out.
Rich
All good ideas, but checking the bottom end would only narrow it down. In 1970 the LT1 (370hp),and L46(350 hp), shared the same bottom end, as well as head numbers. All the parts that are LT1 specific could easily be added to the L46.
Fact of the matter is, if your 69 is a L-46, it sounds like you have most of the interals for it. Might be easier to verify what the 69 should be.
Melting Slicks
Joined: Dec 2002
Posts: 2,390
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From: Belmont Michigan
Originally Posted by dennis
All good ideas, but checking the bottom end would only narrow it down. In 1970 the LT1 (370hp),and L46(350 hp), shared the same bottom end, as well as head numbers. All the parts that are LT1 specific could easily be added to the L46.
Fact of the matter is, if your 69 is a L-46, it sounds like you have most of the interals for it. Might be easier to verify what the 69 should be.
Fact of the matter is, if your 69 is a L-46, it sounds like you have most of the interals for it. Might be easier to verify what the 69 should be.
True, Dennis, but the engine is stamped with the code for an LT-1 , not an L-46. Just trying to verify if that's what it is, and not a 400 out of a '75 Impala. :*****
Rich
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From: Austin TX
Accordingly to the console spec plate the original engine was a 350hp sb but since there isn't a vin and the engine code is not correct for that engine I don't think it's the original engine (unfortunately). Right now I don't have a car for this engine but when the time comes I'll take it apart and see if it has lt-1 internals.
Being that StickShiftCorvette was able to buy one over the counter w/o stamping the previous owner of my car might have done the same.
Thanks.
Being that StickShiftCorvette was able to buy one over the counter w/o stamping the previous owner of my car might have done the same.
Thanks.
