Go Back   The Supercar Registry > General Discussion > Technical & Restoration


Reply
 
Thread Tools Display Modes
  #1  
Old 11-26-2022, 12:36 AM
jbtech's Avatar
jbtech jbtech is offline
Yenko Contributing Member
 
Join Date: Apr 2020
Location: Prunedale, CA
Posts: 498
Thanks: 472
Thanked 1,087 Times in 207 Posts
Default Correct Speedometer Adapter 67 L78 D70-14 4.56 Rear

Hello Folks,

What is the correct factory speedometer adapter needed for my 1967 Camaro SS L78 with 4.56 rear and D70-14 tires?

It may take me a long while to find the correct original and I'd like to start the hunt now but need confirmation on the correct part number.

Thanks!

Jose
Attached Images
 
__________________
Jose Betancourt

67 Camaro L78
Reply With Quote
Attachments - The Supercar Registry SpeedoAdapter.jpg Screen Shot 2023-01-19 at 9.24.33 AM.png Screen Shot 2023-01-19 at 8.07.23 AM.jpg Screen Shot 2023-01-18 at 3.16.43 PM.png
O Garage vBulletin Plugins by Drive Thru Online, Inc.
Click here to view all the pictures posted in this thread...
  #2  
Old 11-26-2022, 12:52 AM
HuggerSS HuggerSS is offline
Yenko Contributing Member
 
Join Date: May 2017
Posts: 498
Thanks: 76
Thanked 921 Times in 190 Posts
Default

I think 4:56 used 735. 736 was used for 4:10 and 4:88
Reply With Quote
The Following User Says Thank You to HuggerSS For This Useful Post:
jbtech (11-26-2022)
  #3  
Old 11-26-2022, 02:55 AM
jbtech's Avatar
jbtech jbtech is offline
Yenko Contributing Member
 
Join Date: Apr 2020
Location: Prunedale, CA
Posts: 498
Thanks: 472
Thanked 1,087 Times in 207 Posts
Default

Yep just found that the 735 is the one I need. Thanks
Attached Images
 
__________________
Jose Betancourt

67 Camaro L78
Reply With Quote
  #4  
Old 11-27-2022, 02:11 AM
Big Block Bill Big Block Bill is offline
Yenko Contributing Member
 
Join Date: May 2004
Location: Elk Grove Village Illinois
Posts: 1,479
Thanks: 1,915
Thanked 689 Times in 288 Posts
Default

Who needs a speedometer when you’re running 4:56 gears, just listen to the music the motor is making and guess! But I’m just sayin.

Bill
Reply With Quote
The Following 2 Users Say Thank You to Big Block Bill For This Useful Post:
jbtech (11-28-2022), lbnaz (11-28-2022)
  #5  
Old 01-18-2023, 02:44 PM
jbtech's Avatar
jbtech jbtech is offline
Yenko Contributing Member
 
Join Date: Apr 2020
Location: Prunedale, CA
Posts: 498
Thanks: 472
Thanked 1,087 Times in 207 Posts
Default

Adapter Found. Thanks everyone
__________________
Jose Betancourt

67 Camaro L78
Reply With Quote
The Following User Says Thank You to jbtech For This Useful Post:
napa68 (01-18-2023)
  #6  
Old 01-18-2023, 08:15 PM
jeffschevelle jeffschevelle is offline
Yenko Contributing Member
 
Join Date: Oct 2008
Location: Concord, NC
Posts: 357
Thanks: 2
Thanked 710 Times in 175 Posts
Default

An adapter p/n 6476655 was first listed in the July-67 parts book, but only for 67 Z28 (7.35x15 tires) with 4.88 gears. See: http://www.gmpartswiki.com/getpage?pageid=10455

The line above that lists p/n 3905497 as "67 Camaro (4-spd, w/ P/Trac.) (350)", without any ratio references. And it says "driven gear" rather than "Adapter Assy". But that is not correct, as p/n 3905497 shows up in Chev. truck parts books through at least 1979, listed as an adapter.

So I assume that was the very common bad data entry in the parts books when an item was first used. If so, perhaps 6476655 was an adapter for 67 Z28's with 4.88, and 3905497 was an adapter for all OTHER manual trans 67 Camaros (with 14" wheels) that required an adapter (so 4.10, 4.56, AND 4.88 ??) But see below that suggests that the July-67 listing may be even more wrong than that.

***
The page posted earlier above is from the November-67 book (so issued after 1968 production had started and part numbers may have changed). For 6476736, it continues the incorrect "driven gear" description, but changes the applications to all Camaro 4-Spd with 4.10 or 4.88 (without any model or tire limitations).

Then it lists 6476735 as 4.56, but limited to Z28 only (7.35x15 tires) -- So the "Z28 only" listing shifted from 4.88 gears in the prior book to 4.56 gears in this one. But you could also get a 4.56 behind a 350 or a 396/375, so the limitation to Z28 tires would leave all other 4.56's with no adapter.

If the Nov-67 descriptions are off, and 6476736 is ALL manual Camaro 4.10 and 4.88, and 6476735 is ALL manual Camaro 4.56 (and not just Z28), then that begs the question whether the July-67 book's reference to one adapter (6476655) for Z28 4.88 only was really for all manual Camaro 4.56's, and the other adapter (3905497) was really for all manual Camaro 4.10's and 4.88's ???

***
On a related question, does anyone know for sure whether any adapters were originally used at all on any 66 and 67 Chevelles? I have a factory 4.88 67 Chevelle. There was no adapter, but when I got the car the engine was gone and the speedo cable was hanging loose. So there could have been one that was tossed.

Given that final drive ratios on a Camaro and a Chevelle with the same trans, rear gear, and tire circumference would be exactly the same, it seems logical that if a 67 Camaro needed an adapter for the 4+ ratios, then a Chevelle should have needed one too.

But there is nothing showing an adapter in the Chevelle AIM for 66 or 67. And in the Chevelle parts books, Group 4.329 (where the adapters are listed) did not have any adapters listed in the Oct-66 and prior books, except for Corvairs. See here: http://www.gmpartswiki.com/getpage?pageid=77360

The first time an adapter shows up for a Chevelle is on the page posted earlier above from the Nov-67 book. And it only references usage on 68 Chevelles, but still no 66-67 Chevelles applications.

So the books suggest no adapter on 66-67 Chevelles, but that defies logic if a Camaro needed one.

Thanks!
__________________
Jeff Helms
65 Z16 Survivor
65 Z16 drag car
66 Chevelle L78 unrestored
67 Chevelle L78 unrestored
67 Camaro SS350 Survivor
Reply With Quote
  #7  
Old 01-18-2023, 08:43 PM
Steve Shauger's Avatar
Steve Shauger Steve Shauger is offline
Administrator
 
Join Date: Aug 2000
Location: Long Island, NY
Posts: 4,909
Thanks: 1,822
Thanked 6,078 Times in 1,322 Posts
Default 67 l78 Camaro 456 rear trans adapter.

Jeff for reference there is an unrestored example with a 6476736 .777 adapter. The variable is the all important drive gear. My car is also equipped with 456 and when purchased did not have an adapter and the speedometer reading is accurate. In a few months I will have access and will know what driven gear is in the original transmission.
.
Attached Images
 
__________________
Steve Shauger
The Supercar Registry
www.yenko.net

Vintage Certification™ , Providing Recognition to Unrestored Muscle Cars. Website:
www.vintagecertification.com
Reply With Quote
  #8  
Old 01-18-2023, 10:20 PM
jeffschevelle jeffschevelle is offline
Yenko Contributing Member
 
Join Date: Oct 2008
Location: Concord, NC
Posts: 357
Thanks: 2
Thanked 710 Times in 175 Posts
Default

Quote:
Originally Posted by Steve Shauger View Post
Jeff for reference there is an unrestored example with a 6476736 .777 adapter.
Is that picture a Camaro? What year? And what rear gear?

Quote:
Originally Posted by Steve Shauger View Post
My car is also equipped with 456 and when purchased did not have an adapter and the speedometer reading is accurate.
Is yours a 67 Camaro? L78 or Z28?

Thanks!
__________________
Jeff Helms
65 Z16 Survivor
65 Z16 drag car
66 Chevelle L78 unrestored
67 Chevelle L78 unrestored
67 Camaro SS350 Survivor
Reply With Quote
  #9  
Old 01-19-2023, 12:07 AM
Steve Shauger's Avatar
Steve Shauger Steve Shauger is offline
Administrator
 
Join Date: Aug 2000
Location: Long Island, NY
Posts: 4,909
Thanks: 1,822
Thanked 6,078 Times in 1,322 Posts
Default

Quote:
Originally Posted by jeffschevelle View Post
Is that picture a Camaro? What year? And what rear gear?



Is yours a 67 Camaro? L78 or Z28?

Thanks!
The adapter I posted is on a car identical to mine. It's a late build L78 camaro with 456 gears.

I also mentioned my car has no adapter now but it may have been discarded, however the speedo is accurate.
__________________
Steve Shauger
The Supercar Registry
www.yenko.net

Vintage Certification™ , Providing Recognition to Unrestored Muscle Cars. Website:
www.vintagecertification.com
Reply With Quote
The Following User Says Thank You to Steve Shauger For This Useful Post:
napa68 (01-19-2023)
  #10  
Old 01-19-2023, 01:26 AM
Too Many Projects's Avatar
Too Many Projects Too Many Projects is online now
Yenko Contributing Member
 
Join Date: Oct 2020
Location: Town of Troy, WI
Posts: 4,049
Thanks: 2,101
Thanked 2,848 Times in 1,348 Posts
Default

There are a few different drive gears that mate with the driven gears. By Jody Haag's comments in threads, for a 4.56 rear ratio, the drive gear should be 6 teeth while the driven gear should be 20 teeth. This would eliminate an adapter. There are 2 different diameter drive gears also and corresponding driven. They must be matched.

Interesting thread here. Certainly not definitive, but educational.
https://www.camaros.net/threads/munc...o-gear.218963/
__________________
Mitch
1970 Chevelle SS
1966 Chevelle SS
1967 Camaro ss/rs
1938 Business coupe, street rod
2000 FXSTS, original owner, 13k miles
Reply With Quote
The Following User Says Thank You to Too Many Projects For This Useful Post:
jbtech (01-26-2023)
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 02:26 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.