70 LT1 suspension resto dilemma
I bought a 70 LT1 last year with an interesting history. It was a special order by a California dealer for the original owner who was a Viet Nam vet at the time. He ordered the car Laguna grey and bright blue interior with what he called the ZR1 package in his letter. Now I'm sure the car is not a ZR1 ( car has a radio and electric windows), but I am curious about the suspension. In the original owners letter he talks about the special brakes, etc on the car. The car came to me with dual pin brakes ( #5469588 ), heavy duty sway bar (15/16) rear spring ( 7 leaf ) and HD front springs. I only have a p.o.p. and no way to prove HD suspension other than the letter, so should I ditch all this stuff and just do the resto with standard parts? I want to do as well as I can with this car because the drivetrain is all there and the color combo is rare. What do you think?
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Re: 70 LT1 suspension resto dilemma
A radio and power windows can be installed easier than dual pin brakes, heavy duty sway bar, 7 leaf rear spring, and HD front springs. What indications do you have that it is NOT a ZR1. Does it have the original engine? If so, what is the suffix? If not, what is the suffix from the POP? -
Re: 70 LT1 suspension resto dilemma
Sal-----
I thought that power windows was an available option even if ZR-1 was ordered. If so, the radio would be the only thing added and, as you say, that would be quite easy.
However, the engine suffix code from either the engine and/or POP should be the definitive piece of information. That will "tell all tales".In Appreciation of John HinckleyComment
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Re: 70 LT1 suspension resto dilemma
Kim since you have the POP, is the original owners name still on it? If it is with the address have you tried to contact the original owner?
I have found the Corvette order copy in my original owner 1970 behind the tack and in my original owner 68 the order copy was behind the radio. If yours is still in the car it will verify the options. Removing the gas tank to see if the tank sticker is still readable is another option.Comment
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Re: 70 LT1 suspension resto dilemma
As the owner of a NA9 equipped '70 LT1/ZR1, I'm curious about who the selling dealer was for your car. My build sheet specifies dealer #183, but the zone number is unreadable. Can you tell me where your car was sold?
As mentioned, your POP and engine suffix stamp will tell you about the car's original config. BTW - Power windows were NOT available on ZR1's - only deluxe interior and tilt/tele were offered as options when the Special Purpose Engine Package was specified.Comment
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Re: 70 LT1 suspension resto dilemma
The suffix on the pad is CTU, stamp on the trans is B. The previous owner contacted the original owner. He sent a letter about the car and the ZR1 option. I think he may have had just HD brakes, etc. The dealer was Charley Graham in Blythe, CA. I have not tried to contact the original owner since previous owner did and recieved a letter. I'm sure he would not mind me calling, but is that going to help prove the car had J56 or F41? Thanks!!Comment
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Re: 70 LT1 suspension resto dilemma
Kim - Just curious - what are the last 5 digits of your VIN? Just trying to get a handle on if it's an early or late LT1. And very interested in finding out if the dealer installed the J56 - or if somehow they got the factory to do it.
Quick question - are there any paint daubs on the brake backings? Crayon markings on the rear cross member? These are two tell-tale signs of factory installed J56 and F41. If yes, I'd be happy to compare notes.
PS- here's a link to a feature article about my '70 ZR1 in this October issue of Corvette Fever:
Best,
Dan PepperComment
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Re: 70 LT1 suspension resto dilemma
Joe-
I'm basing my statement on GM published specifications for the '70 ZR1 Special Purpose Engine Package. This stated that no wheel covers, power or convenience options (windows, steering, defrost, radio) could be ordered with the package. Only Leather/deluxe interior trim and T/T column.
Admittedly, PW would be a nice feature for a performance car as I understand that a number of "raced" cars were ordered with PW as the weight was negligible (or even less?) and the benefits high for quick pit stops and ventilation without fumbling with knobs and reaching across the passenger seat.
All the known '70 ZR1's are sans PW, but suppose it's not impossible it happened. Just another case for factory docs to back it up.Comment
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Re: 70 LT1 suspension resto dilemma
Dan,Kim - Just curious - what are the last 5 digits of your VIN? Just trying to get a handle on if it's an early or late LT1. And very interested in finding out if the dealer installed the J56 - or if somehow they got the factory to do it.
Quick question - are there any paint daubs on the brake backings? Crayon markings on the rear cross member? These are two tell-tale signs of factory installed J56 and F41. If yes, I'd be happy to compare notes.
PS- here's a link to a feature article about my '70 ZR1 in this October issue of Corvette Fever:
Best,
Dan Pepper
The last 5 digits are 02744. Only daub of paint was on inside caliper at the front on driver's side. No crayon markings. Cast on calipers are 5489588 if that helps any. KimComment
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Re: 70 LT1 suspension resto dilemma
Kim----
I don't think the number is 5489588. I don't think any numbers in the 548XXXX series were ever released. I think the number is actually 5469588 or 5469589 (BOTH casting numbers may have existed).
One or both of these numbers is a rather rare caliper casting. The ones I have seen carry an "X" casting number suffix. These caliper castings omit one of the brake line fitting bosses which make regular Corvette front caliper castings machinable for use on either side. In other words, these castings are side-specific.
I was told that these castings were used for the front calipers for 1969 Camaro with 4 wheel disc brake option. This application used Corvette-design, 4 piston calipers at all 4 wheel positions. I was told that the omission of the superfluous brake line boss was necessary due to some sort of interference problem on the Camaro application.
These castings could also have been used for Corvettes with J-56, though. At least, I don't see any reason why they could not have been used.In Appreciation of John HinckleyComment
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Re: 70 LT1 suspension resto dilemma
I still go back to my question -- do you guys think I should leave the brakes, sway bar, front and rear springs on the car with no proof other than a letter from from the original owner stating he had the ZR1 brakes etc.? What would you do? KimComment
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Re: 70 LT1 suspension resto dilemma
I'd leave the car as-is Kim. Since there is no clear answer as to whether the car was built this way by the factory or by the dealer, you may inadvertently undo a part of history. The car has been in this configuration for almost 40 years- what's the rush to change it?Comment
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Re: 70 LT1 suspension resto dilemma
I assume since you're asking theses questions on the NCRS tech board that you're considering having the car Flight Judged. If yes, you'll need to remove the J56 brakes and F41 bits to receive the most points. The rules are clear; if the configuration is not typical, and not documented by GM to show the car left the factory that way, it will receive a deduct. It's not too hard to remove/replace these parts in order to go thru the judging process, so if it were me and receiving a Top Flight was important - I'd restore per the NCRS standard of known/typical configuration, have the car judged at a Regional Level event, then bolt the parts back on and drive the car.
The '70 LT1 was one of Zora's last true expressions of a of what a Corvette should be; a sports car that stops as well as it goes through the straights and curves. Can't blame the original owner for wanting even better performance than the standard single-pin, non-insulated piston brakes and softer suspension provided.
If restoring the car do drive and you're not married to the idea of earning a Top Flight award (which, based on raw score may still be possible even with the mods - you may want to do the math), I believe the story and provenance are worth more than a few stinking points.
Points? We don't need no stinking points!
PS- I plan on leaving the home-made tow bar mounts bolted to the frame of my 4:56 posi-equipped ZR1 after restoration/during judging. To me, it's just another part of "provenance" that IS the car - factory or not.Comment
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