Donnybrooke Green '70 #s LT-1 Corvette Convertible
 

Still waiting for these incredible '70 LT-1 Corvettes to hit their stride in value. Seller claims only 1278 were produced in '70 - is that correct? Probably a $100k car in a few years.

Link to 1970 LT-1 Corvette Convertible eBay auction

https://i.ebayimg.com/00/s/MTA2N1gxN...7.JPG?set_id=2

https://i.ebayimg.com/00/s/MTA2N1gxN...7.JPG?set_id=2

https://i.ebayimg.com/00/s/MTA2N1gxN...7.JPG?set_id=2

https://i.ebayimg.com/00/s/MTA2N1gxN...7.JPG?set_id=2

194670S403013

That is a pretty car, but the pictures are all glamor shots. No pictures of tags, engine stamp, chassis, or paperwork (if available). You really can't come close to a buying decision with what they posted.

----This good looking 70 LT1 appears to be a pretty decent 70 LT1. As I type this I'm hoping there's a buyer out there that loves a green on green color combo. That's a hard hump to overcome....Bill S

Totally agree. Growing up in WI nearly every older vehicle was green on green, some even triple green. It’s growing on me….

He is close. 1287 LT-1s. How many were convertibles is conjecture.

Probably less than 500 if the ratio on ALL 70 Corvette Vert vs Coupe holds up.

Good looking Fantastic Plastic.:burnout:

I can't agree more. That's a hump I just don't see me ever getting over with a Corvette, Camaro, or a Chevelle. Having the upgraded custom interior option that might make it an easier pill to swallow. Bill

I'm going to stick my neck out and say...The green exterior was common, but the green interior is not, especially on an LT1.

----That would have been a great upgrade, but green deluxe interior was not available in 1970. To Bad! Saddle with the deluxe interior would have been a knockout....Bill S

Folks - a yenko.net member sent me the deck stamp from this car - see attached.

Ooooooffdah!

----Tony,,,I got the same message. Someone got the deal of the year! I never saw the pad....Bill S

Anyone from the site get it?

CTV suffix code wow, a ZR1 vert hiding in plain site. Jeez.

Here’s the stamp pad of a car built 6 units later. This serial number stamping is what I would consider typical for 1970 production.

This from the Green/Green LT-1 seller:
Hi,we did have the car inspected and confirmed it was not a real ZR-1 and we are of the opinion it was re-stamped when it was restored as was the inspector.A very nice Stingray for sure,but it's not a real ZR-1.We had the Stingray inspected by an independent Classic car Appraiser who is very knowledgeable.Beyond the engine stampings,there are other indicators that this Corvette is not a ZR-1.ZR-1's did not have radios or shielding on the ignition wires or an antenna.This car has a radio,and you see where the hole for the antenna mount was filled in and painted over.
The M21 transmission,came from a '69 Nova and the rear end date codes are not correct.
It's missing some options/features that a ZR-1 would have.
It does have the right Block stampings and overall,a very nicely restored Stingray which drives exceptionally well and had the performance of a ZR-1,but without any historical data from Chevrolet to prove otherwise,it's not a ZR-1 in our opinion.
The buyer did collect the car,and as far as I know the car is still in our local area.

Kind regards,
David Bruski

I was going to say restamp.

While on this topic; I know there are significant differences between a "plain" LT-1 and a ZR1 such as brakes, suspension and mandatory M22.

I have never been able to find a definitive answer on what would be different in the engine. There has to some difference to warrant a different engine code. And it can't just be the M22.

I’ve always wondered this exact thing. Maybe GM snuck the Off-Road camshaft into the LT1!

One difference is the clutch diameter. It's not unusual to see an LT1 assembly code ground and restamped as a ZR1 by changing out the clutch. I looked at a 1972 ZR1 that was prepared this way, no ZR1 engines, grind and restamp the LT1 code and change the clutch.

So did the ZR1 use a 403 bell housing with 10.5 clutch. I know my LT-1 has 621 bell housing with 11 inch clutch.

Another member suggested it may be no ignition wire shielding because the ZR1 did not offer a radio.

Can anyone confirm?

An LT1 could be had with no radio, so that wasn't the change. It was the bell housing and 10.5 inch clutch, Lynn. It used the L88 starter that was dated 1968 and was in left over inventory.

So now that this thread is already slightly of the rails, how about another rabbit hole?

Always wondered why some vehicles got the 10.5 clutch and others the 11. Wasn't based on power, as ZL1s got the 10.5 as well as the Z/28.

In theory, the 10.5 would be easier to shift at high RPM. Maybe based on expected rear gear?

That is a good question, I never understood that, either.

You can definitely tell the difference as far as the ZR1 engine revving faster with the smaller flywheel. ZR1's are really neat.

That small flywheel was also in the 65 L78 Corvette's. Which ultimately proved to be the demise of many a 65 L78:3gears:

----Lynn,,,It's all about the weight of the flywheel. Less weight faster ability to gain RPM. At Classic Motors (circa 1977-78) I had a 67 435 convert that had been drag raced prior to my ownership. It had the factory flywheel set-up. we had to yank the motor for some work and along with that I decided to install the L-88 flywheel, bellhousing, and clutch assembly (10 1/2). That 435 became probably the fastest one I have ever had with a basicly stock engine. The car was carrying a 456 gear set which would also help a bunch, but lower more normal gears would also benefit....Bill S

That’s why racers like to put aluminum flywheels on their motors.

My Scarab had a light weight flywheel and it would rev to 8,000 RPM before you knew it.

So, it sounds like the 10.5 clutch is the reason for a different engine suffix than a regular LT1. That actually makes all the sense in the world since bellhousings have orange overspray after being painted on the engine at Tonawanda. Clutch & PP plates were obviously installed at Tonawanda before the bellhousing and not at the final assembly plants.