67HEAVEN
Well-known user
Are you, and the car, in the UK? If so, when did the car cross the pond? Pethaps the top sticker was related to export. Fun stuff!
The Corvette LS-7 that never was...
- Thread starter 67HEAVEN
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sublimemike
Well-known user
The top sticker relates to being legal only for off road use only. GM sold the LS7 long block part no. 3965774 as an after market part for off road use ONLY. Car has been in UK about 3 years via canada
67HEAVEN
Well-known user
Cool. That long block included cast iron open chamber rectangular port cylinder heads with 2.19 intake and 1.88 exhaust valves, “dimple” 7/16 bolt steel rods, and forged 12.25 compression pistons. The cam is a flat tappet solid lifter 560 intake and 600 exhaust design, necessitating setting the valve lash regularly for ultimate performance.
How often are you lashing the valves? As you know, when you hot lash it gets messy. I actually cut the top off an old valve cover and temporarily installed it to help minimize splashing oil all over the place.
sublimemike
Well-known user
I have 074 aluminum heads balanced and blue printed. Built by Diamond engineering and Bill king race engines (can am Mclaren race cars). Car has been looked over and signed by Gib Hufstaeder, Tom Langdon and Tony de Lorenzo.
As far as the lash I do mine cold and add on 0.02" to compensate. Doing hot is very messy. I'm not sure if this correct but was what i was told. the cam Jake specified is an early roller to the best of my knowledge I don't have the specs but in reality its a bit much for road use.
As far as the lash I do mine cold and add on 0.02" to compensate. Doing hot is very messy. I'm not sure if this correct but was what i was told. the cam Jake specified is an early roller to the best of my knowledge I don't have the specs but in reality its a bit much for road use.
sublimemike
Well-known user
CORRECTION......It's a ZL1 cam
67HEAVEN
Well-known user
Yes. Then it's GM part number 3959180. It's a very radical solid-lifter cam that is a pain on the streets, as you know. I still have mine sitting in my shop along with the 427. I had modified my '67 L71 into a L71/L88 hybrid many, many years back, when leaded fuel and decent octane were available.
The solution, for me at least, was pulling out the 427 and replacing it with the ZZ502 plus an enhanced (compared to the stock 502) hydraulic cam and roller rockers. Now, it will start when cold, I don't have to lash the valves, I can get fuel that it's happy with (without driving to the local airport), and the power brake boost works at slow engine speeds.
sublimemike
Well-known user
Ha ha , yes the cold starts. I was able to fit a manual choke to mine and it improves. Still takes some cranking when not used a while. Once you find some space to get the cam on song its great......just watch the brakes LOLBy the way, thanks for jumping in on this. With the involvement of a few others in separate threads, we're getting going here in C1, C2 and C3.
This is where the history is, people!!!
67HEAVEN
Well-known user
By the way, sublimemike, you may find it interesting that I ordered a new 1972 Chevrolet Kingswood (the station wagon model equivalent to the Impala) with a LS5 454. I waited 8 weeks for it to be built. It was a beautiful car that I should have kept. Why a wagon? I was running a small contracting company with several Chevy vans, but the boss needed a car.
By 1972, North American horsepower ratings were changed from gross to net, so the LS5 454/390hp (gross) changed to 454/270hp (net). The base engine was a 350 c.i., but once you've had a big-block, you can't go back. LOL.
This photo was taken on the east coast of Canada. in 1973.
By 1972, North American horsepower ratings were changed from gross to net, so the LS5 454/390hp (gross) changed to 454/270hp (net). The base engine was a 350 c.i., but once you've had a big-block, you can't go back. LOL.
This photo was taken on the east coast of Canada. in 1973.
sublimemike
Well-known user
BB wagon ,nothing wrong with that. Dave Billeudea was running 11's in his 440 wagon last year at the Pod. Ever run your car at the strip?
Daytona Vette
Well-known user
I have the Mark IV 454 from the GM performance parts 366250 it has many of the same goodies as the LS7, I wanted the LS7 but the 12.25:1 would not have been good on regular pump gas, so I went one down to the LS6 but with the 10.2:1 compression, both have the forget steel crank and rods with the 7/16 bolts, ally pistons and large rectangular port heads (cast iron) both with the solid lifter cam, but the LS7 has the high lift racing cam. this LS6 is supposed to be about 460 bhp, I have never put it on test but I think the figure may be a little high
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67HEAVEN
Well-known user
That's a great engine that, like all hi-perf big-blocks, cries out for headers for peak performance without internal modifications. As good as the Corvette exhaust manifolds were, they cannot touch headers for flow. The beauty of the side-mount Hookers is that the very-long-length individual exhaust tubes from each cylinder join into massive 4" wide side exhaust tubes; much further back than typical under-car headers.. As can be imagined, back pressure is minimal, and if you remove the slip-in mufflers from the side tubes, the horsepower goes up even more. Oh, and the Earth shakes too.
Mine below....
Daytona Vette
Well-known user
Unable to easily use side pipes, whilst the Daytona was having a Body Off, the chassis itself had been finished and was taken to one of our National Club events for display by the restorer (Corvette Kingdom) - it was shown with side pipes (although not mine) but not with my 3 piece alloys with 295 50 15s on the front, for the reason that the tyres caught on the headers when turning to maneuver the chassis.That's a great engine that, like all hi-perf big-blocks, cries out for headers for peak performance without internal modifications. As good as the Corvette exhaust manifolds were, they cannot touch headers for flow. The beauty of the side-mount Hookers is that the very-long-length individual exhaust tubes from each cylinder join into massive 4" wide side exhaust tubes; much further back than typical under-car headers.. As can be imagined, back pressure is minimal, and if you remove the slip-in mufflers from the side tubes, the horsepower goes up even more. Oh, and the Earth shakes too.
Mine below....
View attachment 2183
However, I do have headers and I have been thinking about electronic cut outs, probably shake everything off the shelves when I start it in the garage.
sublimemike
Well-known user
Out of curiosity i called Jake today in the states , his memory is still sharp as a pin. I dug deeper into how he acquired the console plate. as well as a couple of other matters Jake knew a guy that worked at GM and as has been detailed a number of other vette variants were culled at the time prior to 1970 production. I have a copy of the revised production signed by GM executives for 1970. Anyhow a person Jake knew acquired a number of these console plates since they were never going to be used for production. Jake acquired his in a white envelope and given his honesty concerning the rest of the vehicle I have no reason to doubt this a genuine factory produced part - all be it with no official number.I took the liberty of comparing the L88 console plate with the one in your post. It's reasonably well done. As you will note, the L88 characters are all the same size font, and very close together. In the LS7 console plate, the L and the S are taller than the 7, and they are spaced wider. Also, the 4 (in the 427) has a longer horizontal tail that do the two 4s (in the 454). Still, it's pretty well done.
67HEAVEN
Well-known user
It's great to investigate the history of these cars.Some day, I hope mine will be in the possession of my son and that he will carry on the tradition of knowledge, history and respective for what came before us. It'll be a sad day when I turn it over to his care. Maybe he'll let me drive it now and then.
67HEAVEN
Well-known user
Here's a look at a '70 LS5, converted to a race LS7. Neat story - Corvettes on eBay: 1970 LS7 Corvette Racer - Corvette: Sales, News & Lifestyle