POSI traction - Honest question
Thread Starter
Race Director
Joined: Oct 2007
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From: Fairfield, VA
POSI traction - Honest question
I was under the impression all C-3s were posi.
I am reading specs today for fun and Posi is G81 $12.65 option.
Others years have the option as well.
SO - how many POSI rears are really out there?
I am curious.
I am reading specs today for fun and Posi is G81 $12.65 option.
Others years have the option as well.
SO - how many POSI rears are really out there?
I am curious.
Race Director
Joined: Mar 2003
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From: Eustis ( Area 51 Bat Cave ) Fl
How many?
Im not sure, someone with the build numbers will tell us, but i sm guessing most c3s 69 and on have posi,
This bugged me badly, 68 it was an option year, my donor chassis is 68 and could be non posi, not that i need posi and havent even checked it yet but my ocd i will have to swap in a posi unit just because, plus i have seen posts about non posi range from they are weaker to they are junk,
Im not sure, someone with the build numbers will tell us, but i sm guessing most c3s 69 and on have posi,
This bugged me badly, 68 it was an option year, my donor chassis is 68 and could be non posi, not that i need posi and havent even checked it yet but my ocd i will have to swap in a posi unit just because, plus i have seen posts about non posi range from they are weaker to they are junk,
Last edited by The13Bats; Jun 25, 2017 at 05:54 AM.
Race Director
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From: Eustis ( Area 51 Bat Cave ) Fl
Safety Car
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From: Orlando FL
Been good bats! How about you? I recall reading in another thread a while back about posi being standard from 71 on. But I believe 68notray is right... probably very few cars built that were non-posi. My rear chunk is at Advanced Driveline right now, getting the shims & backlash set up. We put new races, bearings, seals, and clutches in.... but had an issue with the carrier shims. Willcox (LOVE those guys!) helped me out with advice & a shim, but we still had problems getting it right, so we sent it over to AD.
Team Owner
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Cruise-In II Veteran
Positraction was optional for 68 and 69 but required with the TH400. Positraction became standard equipment beginning with the 1970 models. For most model years, optional gear ratios could be ordered for the Posi.
Safety Car
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From: Orlando FL
OK.... looking at production numbers (of C3 generation) the posi was an option in 68, 69, and 70.
It is no longer listed as an "option" in 71.
It looks like....
1968, 27,008 out of 28,566 had posi.
1969, 36,995 out of 38,762 had posi.
1970, 2862 out of 17,316 had posi.
Add that up, then add total production for the remaining C3 years, and that should be a close guess.... IF all the various website information is accurate.
It is no longer listed as an "option" in 71.
It looks like....
1968, 27,008 out of 28,566 had posi.
1969, 36,995 out of 38,762 had posi.
1970, 2862 out of 17,316 had posi.
Add that up, then add total production for the remaining C3 years, and that should be a close guess.... IF all the various website information is accurate.
Last edited by oldgto; Jun 25, 2017 at 08:09 AM.
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Safety Car
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From: Orlando FL
Le Mans Master
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From: eastern NC
OK.... looking at production numbers (of C3 generation) the posi was an option in 68, 69, and 70.
It is no longer listed as an "option" in 71.
It looks like....
1968, 27,008 out of 28,566 had posi.
1969, 36,995 out of 38,762 had posi.
1970, 2862 out of 17,316 had posi.
Add that up, then add total production for the remaining C3 years, and that should be a close guess.... IF all the various website information is accurate.
It is no longer listed as an "option" in 71.
It looks like....
1968, 27,008 out of 28,566 had posi.
1969, 36,995 out of 38,762 had posi.
1970, 2862 out of 17,316 had posi.
Add that up, then add total production for the remaining C3 years, and that should be a close guess.... IF all the various website information is accurate.
From the Corvette Black Book... "Previously optional tinted glass, Positraction axle, and 4-speed wide ratio manual transmission were also included in the 1970 base price."
Good luck... GUSTO
Le Mans Master
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From: eastern NC
That's the way I read it. Since the positraction became standard equipment in 1970, the number 2862 seems a reasonable number of optional ratios being ordered.GUSTO
Safety Car
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From: San Antonio TX
An even more peculiar drivetrain configuration was the standard Three speed manual as the base transmission through 1969. So, yeah, it could always be worse than having an open differential.
Race Director
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From: Eustis ( Area 51 Bat Cave ) Fl
I would take 3 over my auto, not cuz i like hunting gears but i feel my old road race theme demands a stick, and a 3 would become a 4 easier than auto to 4
Thread Starter
Race Director
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From: Fairfield, VA
OP HERE - Thanks for the answers! Confirms my feeling.
another issue -
My Old Man bought a '69 Camaro 3-Speed.... Really Dad??? With the 250 6 cyl??
[He gave it to me after he bought a '77 Datsun B-210..
and wondered why an engine was hanging on a rope
on a limb of our Maple tree... shortly thereafter....I was 16 and pulled the straight 6
and put in a 283. I loved that car.]
another issue -
An even more peculiar drivetrain configuration was the standard Three speed manual as the base transmission through 1969.
[He gave it to me after he bought a '77 Datsun B-210..
and wondered why an engine was hanging on a rope
on a limb of our Maple tree... shortly thereafter....I was 16 and pulled the straight 6
and put in a 283. I loved that car.]