Hi, Can anybody list the differences between a base 70 vette and a LT1 other than the hood and motor? I'm looking at a car that is being advertized as a LT1 but does not have it's original motor. Do the tachs have the same redline? Thanks for the help.

 

Tach redlines are definitely different; I think the LT-1 redlines at 6500 and the base motor might be 5500. 1970 LT-1's also never came as automatics nor could they be ordered with AC.
There are a ton of other differences that I am unable to list but, others on the forum should be able to help out.

 

This is from anther post on the For Sale Forum:

"Hope this is helpful:

There are a few things that only a LT-1 would have, some are pretty easy to change out and some are not very easy at all.

in no particular order.

1st. No 1970 or 1971 LT-1 had A/C

2nd. Emission sticker on fire wall behind master cylinder should have letters AX on upper left corner for a 71.

3rd. All LT-1's are 4 speeds. (M20 was std, M21/M22 were optional)

4th. Tach has 6,500 RPM red line on 1970 & 1971 and on 72's w/o AC

5th. All 71 LT-1's came with A.I.R. system. If removed should still have manifolds with holes for the tubes, Car may have headers and if so ask to see old manifolds.

6th. LT-1's had copper radiator W/O an overflow canister on the passenger side fender well. There should also be no holes where one had been mounted.


7th. All 70 / 71 LT-1's had Transistor Ign. system. That may have been removed. But if it is removed look for the 3 holes on the front face of the driver side inner fender well where the Amplifier box was mounted.

Take a flashlight and look in front of the front wheel or open hood and look at it from the front side. 2 holes on bottom and 1 on top.


8th. Should have a Winters snowflake intake manifold with casting # 3959594


9th. LT-1's had a Holley carb. so there is only 1 fuel line, no return line like a Quadra-jet carb. Look along frame rail on passenger side for the single line. Also the fuel tank is different. There should be no nipple on the passenger side, side wall for a return line.

If you lay on your back under the rear wheel you can reach your hand up and feel for an indention on the passenger side. If there is a nipple that is capped off, then beware.

Also the single fuel line on a LT-1 was not the same line that was used to feed fuel on the 2 line set up. So if someone removed the return line the look of the 3/8 line is still different. Not a big difference but if you can look at a car with a 2 line set up then you can see what you do not want to find.

10th. LT-1's had solid lifters, but if the car does not then that is not too big a red flag. Many people do not like them and may have replaced with HYD. lifters during a rebuild.


11th. The hardest to fake and most expensive would be the 4 bolt main block. No # on the outside of the block can verify this.

Only way to verify is to remove the pan or have a lighted optical viewer and remove the drain plug.


12th. LT-1's use 2.5" exhaust pipes like the big block cars. But the manifolds were still 2" set up. So the pipes flair from 2 to 2.5" about 6 inches from the manifold. The exhaust hangar at the trans is also different. Look on line at the Corvette Central site and you can see both 2" and 2.5" hangars.

13th. As I recall the highest rear end gear was 3:36 if trans was a M20

And id Trans was a M21 or M22 the 3:55 was highest gear

M20 3:36 Economy

3:55 Standard

3:70 Performance


M21 / M22

3:55 Economy

3:70 Standard

4:11 Performance

14th. The 71 /71 LT-1 Aluminum valve covers should have a rubber oil cap not a twist in. These covers are very hard to find. All the catalogues sell the twist in cap style.

15th. LT-1's have the same heavy duty half shaft retainers as big block cars. Look at the rear end side yokes, there should be caps with bolts. Base cars used U bolts with nuts.

16th. The rocker arms have a letter O stamped in them.

17th. The balancer on the crankshaft is an 8" unit not a 6""

 

Hey thanks for the quick response to my questions and the valuable info. I was pretty sure the tachs would not be the same as the motors made their hp at diff.rpms, but having the additional info really helps.

 

Is there a vin research service, similar to Pontiac Historical Society, that has production info for a submitted vin?

 

I think you can get something similar for Canadian cars (not positive). Nothing available for us poor souls in the States.

 

the absolute most important characteristic of the LT1 option is the engine, the 15 or so other things if engine is there come in after the engine is verified. in this case, the engine is not there.

there are some characteristics that might make the car worth more than a base engine car, and I would probably pay a little more for a real LT1 car without it's engine. but not much more. it is still a NOM car. Do not pay a high markup for the LT1 option since the engine is NOM.

 

Hi 442,
I agree with jw's thoughts about value.
IF it's a real LT-! car you' need to come up with a 'proper' replacement engine for it to reap the added LT-! value over a base engined car.
Don't dismiss the car just because of the engine question; just don't pay TOO MUCH for it thinking it MIGHT be an LT-! car. Understand what it would take to make this an LT-! again.
Regards,
Alan