1970 LT1 CTV Restoration Questions

[Harry E.]

Hello all

New to NCRS, just picked up pretty decent ’70 LT1, have trivia and several restoration related questions…

1) Have authentic VIN+engine code stamp on block which reflects CTV. Had one experienced Vette judge physically review car while another judge compared my engine code photo with actual ’70 ZR1 (just happened to be in his shop that day…lucky fella), both confirmed authenticity. While my car is not ZR1 for some reason (this is where I need your wisdom), this factory build ended up with CTV motor. Reviewed registry and noted 2 or 3 similar events, so was this simply one of those non-documented options during this year run? And how does this impact value?

Pulled off Internet from 1970 Corvette “CTV” blog response (written by ’70 ZR1 owner):
“The LT1/ZR1 Engine WAS a different assembly than the standard LT1 - Hence the different suffix codes assigned to call-out the non-standard parts required. Although the internals, intake and exhaust were identical to standard version LT1, the CTV suffix code in '70 (and the CGY in '71 and CKZ in '72) were fitted with a 10.5" light weight L88-style flywheel and corresponding 403 bell housingas well as a High-torque L88 ('69 coded & dated) starter with aluminum nose. Some say the ZR1's used a cast-iron balancer pulley, but I've only been able to report stamped units.”

2) My drivers and passengers side door moldings need replacement (top/rear portion); suggestions where I can purchase?

3) Distributor cover appears to be original, wondering if cover supposed to have all those wing-nuts (have seen photos withother versions) and where can one pick up authentic replacement distributorcover hardware?

4) Drivers side seat belt has end piece missing and has been cut, need refurbishment, suggestions?

5) Passenger side rear light cover has small cracks, looking to replace, suggestions?

6) Driver’s side door cover has 2 cracks back where drivers elbow would rest, suggestions for refurbishment?

History: Pink Slip CA title, then NV, no rust, no hits/dings/damage, 26,200 miles, all parts appear to be original, CTV, 4:11, AM/FM

Submitted my info to 1970 registry this AM; Juliet and team have done amazing job keeping that dbase up!

Really appreciate any/all feedback, going forth with authenticity in mind, and of course some 105 octane

Thank you!

Harry

[Jimmy D.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Harry,
Nice car, I'm also new to NCRS and have found this site most helpful. There are several companies you can buy the parts your looking for. Paragon, Corvette Central and corvette America are just a few. If you go to services, publication on the site and look at the Driveline you will find lots of ads that might help. Also a judging book might answer a few of you question. You might get more responses if you can focus your question in one area at a time allowing the experts to answer in their area of experience. I use the search box first to see if I can find what I'm looking for and have learned a great deal just reading the responses. Hope this helps a little, I don't know about the engine stamping differences. The car I bought, the past owner built to LT1 with a CEC engine.

69 corvette convertable 350-350HP
Thanks Jimmy

[Don L.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hi Harry and welcome to NCRS!

Sounds like a nice, and very interesting car. I'm looking forward to hearing more about it and seeing more photos.

I see you're in Nevada? If so, you'll likely not be able to get to Corvettes at Carlisle in eastern Pennsylvania next month. There, you'd find many original parts you're looking for. If interested in reproductions, there's a host of repro houses available to the hobby. A partial list has already been posted here.

I believe your seat belt is repairable. Search this forum for Seat Belt City and give Charlie Santorelli a call. He gets some good feedback from many here, including me.

Hope this helps.

[Terry M.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hello all

New to NCRS, just picked up pretty decent ’70 LT1, have trivia and several restoration related questions…

1) Have authentic VIN+engine code stamp on block which reflects CTV. Had one experienced Vette judge physically review car while another judge compared my engine code photo with actual ’70 ZR1 (just happened to be in his shop that day…lucky fella), both confirmed authenticity. While my car is not ZR1 for some reason (this is where I need your wisdom), this factory build ended up with CTV motor. Reviewed registry and noted 2 or 3 similar events, so was this simply one of those non-documented options during this year run? And how does this impact value?

Pulled off Internet from 1970 Corvette “CTV” blog response (written by ’70 ZR1 owner):
“The LT1/ZR1 Engine WAS a different assembly than the standard LT1 - Hence the different suffix codes assigned to call-out the non-standard parts required. Although the internals, intake and exhaust were identical to standard version LT1, the CTV suffix code in '70 (and the CGY in '71 and CKZ in '72) were fitted with a 10.5" light weight L88-style flywheel and corresponding 403 bell housingas well as a High-torque L88 ('69 coded & dated) starter with aluminum nose. Some say the ZR1's used a cast-iron balancer pulley, but I've only been able to report stamped units.”

2) My drivers and passengers side door moldings need replacement (top/rear portion); suggestions where I can purchase?

3) Distributor cover appears to be original, wondering if cover supposed to have all those wing-nuts (have seen photos withother versions) and where can one pick up authentic replacement distributorcover hardware?

4) Drivers side seat belt has end piece missing and has been cut, need refurbishment, suggestions?

5) Passenger side rear light cover has small cracks, looking to replace, suggestions?

6) Driver’s side door cover has 2 cracks back where drivers elbow would rest, suggestions for refurbishment?

History: Pink Slip CA title, then NV, no rust, no hits/dings/damage, 26,200 miles, all parts appear to be original, CTV, 4:11, AM/FM

Submitted my info to 1970 registry this AM; Juliet and team have done amazing job keeping that dbase up!

Really appreciate any/all feedback, going forth with authenticity in mind, and of course some 105 octane

Thank you!

Harry

Harry,
Jim, is right. You will get better results with one question at a time. What is more the trail you leave will be more helpful to others in the future if you post one question, or at least related questions, one at a time.

1) I NEVER comment on stamp pads based on internet pictures. Even pictures sent via email are too low resolution to detect all but the grossest of restamps. I will say that I have not yet heard of the phenomenon you are describing, and I have been at this for a long time. Information about your bellhousing casting number and starter numbers and dates will also be needed to sort through the engine mess.

2) You are asking about door moldings, but your picture shows weatherstrip. Maybe it is my advanced age, but that confuses me.

3) Based on the VIN number on the stamp pad, and assUming that is the VIN of the car, you should have all those wing-bolts. Jim's suggestion that you get the Judging Manual is a good one. The new 1970-72 TIM&JG is supposed to be available at Carlisle. I didn't attend the board meeting following the Convention in Rhode Island, so I don't know if that agenda has changed. Stay tuned for more official announcements.

4) 5) 6) & back to 2) There are advertisers in The Driveline who can supply all your needs for these questions. The quality of the reproduction parts, and services in the case of the seat belt, may be more or less desirable. Start with a search of this board (as Jim suggested) and then ask your quality questions in a post specific to that subject. Shotgun posts don't do well here.

[Joe L.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hello all

New to NCRS, just picked up pretty decent ’70 LT1, have trivia and several restoration related questions…

1) Have authentic VIN+engine code stamp on block which reflects CTV. Had one experienced Vette judge physically review car while another judge compared my engine code photo with actual ’70 ZR1 (just happened to be in his shop that day…lucky fella), both confirmed authenticity. While my car is not ZR1 for some reason (this is where I need your wisdom), this factory build ended up with CTV motor. Reviewed registry and noted 2 or 3 similar events, so was this simply one of those non-documented options during this year run? And how does this impact value?

Pulled off Internet from 1970 Corvette “CTV” blog response (written by ’70 ZR1 owner):
“The LT1/ZR1 Engine WAS a different assembly than the standard LT1 - Hence the different suffix codes assigned to call-out the non-standard parts required. Although the internals, intake and exhaust were identical to standard version LT1, the CTV suffix code in '70 (and the CGY in '71 and CKZ in '72) were fitted with a 10.5" light weight L88-style flywheel and corresponding 403 bell housingas well as a High-torque L88 ('69 coded & dated) starter with aluminum nose. Some say the ZR1's used a cast-iron balancer pulley, but I've only been able to report stamped units.”

2) My drivers and passengers side door moldings need replacement (top/rear portion); suggestions where I can purchase?

3) Distributor cover appears to be original, wondering if cover supposed to have all those wing-nuts (have seen photos withother versions) and where can one pick up authentic replacement distributorcover hardware?

4) Drivers side seat belt has end piece missing and has been cut, need refurbishment, suggestions?

5) Passenger side rear light cover has small cracks, looking to replace, suggestions?

6) Driver’s side door cover has 2 cracks back where drivers elbow would rest, suggestions for refurbishment?

History: Pink Slip CA title, then NV, no rust, no hits/dings/damage, 26,200 miles, all parts appear to be original, CTV, 4:11, AM/FM

Submitted my info to 1970 registry this AM; Juliet and team have done amazing job keeping that dbase up!

Really appreciate any/all feedback, going forth with authenticity in mind, and of course some 105 octane

Thank you!

Harry

Harry------


ZR-1 engines were scheduled to receive the cast iron crank pulley but, apparently, no known originals are so-equipped. The primary difference between the LT-1 used in the ZR-1 and the normal LT-1 was the flywheel, clutch and bellhousing, just as you've found. If yours has the 621 bellhousing used on non-ZR-1 LT-1's, then either the factory made a mistake when they coded the engine or the flywheel, clutch and bellhousing were changed at St. Louis.

If the breaks on the door panel pictured are the only problem with the panels, I'd be highly tempted to try to repair them with an interior repair kit available from Permatex. It might not look perfect, but you'll retain the original panel.

Wing nuts on the distributor RF shielding are the way it was originally done.

[Harry E.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Great feedback Jimmy. This being my first post I obviously still have my "training wheels" on and will pare future posts down per your input. The overall NCRS response level of detail is very impressive and I will research those companies references you mention, so thanks again for your response. BTW, very nice car you have there, had one myself....back in the day (19 years old). Enjoy your convertible (I am jealous) and all that HP under the hood

Harry

[Harry E.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hi Don

Thanks for your feedback and invite to the (cooler and greener) east coast. Yes, really want to keep my car pure and authentic so such replacement and/or refurbishment resources are paramount. Will search for Charlie's SBC...great suggestion!

Harry

[Harry E.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hi Terry

Yes, one question per post going forward...agreed.

Correct Terry, weather-stripping needs to be replaced; thank you for the correction

The CTV stamp discovery was pretty exciting yet nerve racking as I made this LT1 purchase from a very good friend off a handshake (old school). Could not even test drive car at the time (brakes were being changed) so told my buddy purchase contingent on test drive results. After returning several days later, he calls me back to his office, and I walk in to see all sorts of legacy 1970 Corvette books scattered across his desk, with more and more excitement in his voice as our conversation progressed. He said we took much harder look at your numbers and your car has CTV motor installed. My response, "how the heck did that happen?" He cited the strike that year, possible weekend activity during my build, and to keep assembly line rolling, production used what they had at the time.

I thoroughly reviewed the stamp with seller and his most experienced Corvette guy (cited him on my initial post) and all appears legitimate. That CTV was installed during production with preceding car VIN as proof. I felt even more comfortable when NCRS judge in CA compared my photos (sent him several) with actual ZR1 in his shop; he said all looked fine, buy the car and run

Still need to confirm all those unique parts exclusive to CTV (between bell housing and pulley) and will provide additional posts once I secure those results. The couple CTV LT1's on 1970 registry also gave promise so my car is obviously not the only one with this configuration. At this point my pals production scenario (use ZR1 engine since its the only one we have today...keep the line rolling) sounds like the most plausible scenario.

Really appreciate the feedback!

Harry

[Harry E.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hi Joe

Thanks for the timely feedback. Once I get my car up on a lift again will send follow-on post with those results.

Yes sir, want to retain the original panel so appreciate your ideas mentioned

Good to hear re distributor wing nuts, have seen several hybrid designs on LT1 photos

Harry

[Patrick H.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

2) My drivers and passengers side door moldings need replacement (top/rear portion); suggestions where I can purchase?
There is only one company making the door weatherstrips, but they are sold by almost all the catalog dealers. Buy them based on price.

4) Drivers side seat belt has end piece missing and has been cut, need refurbishment, suggestions?
See other comment regarding Charlie Santorelli.

5) Passenger side rear light cover has small cracks, looking to replace, suggestions?
They are easily available used if that will then match the patina of the other 3 lenses. Note that they do have a mold date on them; just be sure not to get one too early or too late. Otherwise you can buy them new as well from one of the usual catalogs.

6) Consider checking with local high end used car dealers (Mercedes, Lexus, etc). Someone usually does their interior repairs, and they may have suggestions as to where to go to have this done professionally.


Harry

See my comments in red.

From what I can see it appears that the car has mostly been restored. Is that the appearance in person as well?

[Don L.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Patrick makes an excellent point on door panel vinyl repair. I shudda thought of this, since this is exactly what I did to repair a small crack in my auxiliary hard top's headliner. They healed the wound with no way to tell it was repaired. Amazing!

[Harry E.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Yes, that is great idea and we have plenty of high-end car dealers here in Las Vegas so I can check into that option.

Thank you both!

[Harry E.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Hi Patrick

Now you see, your answers (and several others) are why I wanted to join NCRS in the first place. Just gives me goosebumps, how much you guys know, and your passion for these cars. Just amazing how much you share with new guys (myself) and your colleagues. Really appreciate everyone's inputs!

So how nice is the car, well I actually gave you everything I could find on my initial thread list and do not know of anything else wrong, broke, requiring replacement, etc. Seller and I initially spent a full hour or so under the car and I was taken back by how clean, original, and defect-free it was. I obviously do not know the '70 build that well but do know it looks well cared for, well maintained, and most important everything appears to be original. My friend told me pains they went through rebuilding original parts (i.e. fuel pump and carb) as his team has been working on this car some 10-12 years now (when original owner brought it in) and they would go to any extreme to maintain originality.

Would give paint a "9", rides extremely well, feel very fortunate (blessed) to even own it, and now I just need to drive safe and maintain all original parts. Will write follow-on note once I confirm CTV starter and bell-housing; more forthcoming.

Harry

[Terry L.]

Re: 1970 LT1 Restoration Questions and CTV Motor Trivia

Welcome aboard Harry,

Congratulations on your corvette, Looks like an interesting car. It appears your car may have originally been shipped to California. I noticed you have a yellow emissions sticker above the brake master cylinder and the additional emission hoses from the PCV. I would be interested to know your carburetor part number and list number, the part no. should be 3973121 with a list no. 4489. There should also be a vapor canister behind the drivers side fender skirt below the vacuum canister.

Terry

[Harry E.]

Re: 1970 LT1 CTV Restoration Questions

Hi Terry

Appreciate the welcome and all the great info, rookies like me really need the help!

Per quick search, 2 possible carbs came on '70 350/370, with latter placed on emissions applications:

370

4-Speed

Holley

4150

3972121

370

4-Speed/ECS

Holley

4150

3972123

I have the latter (3972123, list 4489, 953), shown in my attached photos (not 3973121 you mention)

Took additional pics of area directly behind drivers fender (lower in engine bay), emissions stickers, and carb

Harry