Author Topic: 12 bolt applications  (Read 2583 times)

67 kemie ss

  • Member
  • ***
  • Posts: 35
    • View Profile
12 bolt applications
« on: November 28, 2006, 02:50:59 AM »
Hey
Haven't posted in awhile, but was hoping someone might provide input

I know that it was possible to order a 3.73 rear end ratio (12 bolt) with a Powerglide in 67, but was it at all usual or even recommended?    3.73 strikes me as a bit aggressive for a 2-spd auto trans. 

Thanks 

hotrod68

  • Hero Member
  • *****
  • Posts: 520
  • almost finished
    • View Profile
Re: 12 bolt applications
« Reply #1 on: November 28, 2006, 04:57:53 AM »
3.73s in a 12-bolt with a Powerglide were available with the SS package, but my White Book shows only 2281 cars were built with 3.73s, so it was definitely unusual. From my experience with Powerglides--and I unfortunately had a lot back then!--they were weak, grocery-getter transmissions from the factory and nobody ordered performance stuff with them because they couldn't stand the gaff. A puny L48 350 was strong enough to tear one up in no time if it was abused, so as a practical matter the performance cars mostly got ordered with a 4-speed and lower gears. In those days automatics were almost primitive--high-stall converters hadn't really come on the scene yet--and nobody ordered performance gears with one. That's my take on it, for what it's worth.
HotRod'68  1968 SS350 coupe undergoing frame-off resto/rod. 386/350/4.11s
Butternut Yellow    black standard interior

lakeholme

  • Hero Member
  • *****
  • Posts: 2240
  • *68-12D L30/M35*
    • View Profile
Re: 12 bolt applications
« Reply #2 on: November 28, 2006, 02:42:20 PM »
Listen to Hotrod...  Anyone who drove aggressively or had a teenager in the 60s knew about the Powerglide "slip".  In other words, if you drove aggressively, it was only a matter of time once you started feeling that slip in your glide.  My sister personally proved this in 3 months from her 16th birthday on a 67 Chevelle.  When the THM 350 came out in 69 they quickly outsold the glides and for good reason.  If you wanted power and performance in 67 you drove a stick.

In recent years, I've had a 57 Bel Air, a 61 Impala, and now, a 68 Camaro with glide.  They've all done fine, but my purpose in each of those cars was for cruising and shows.  If I planned to do more on the performance side, I'd at least put in a THM350.
Phillip
HNR-AACA, Senior Master
Charlotte Autofair, Sept 24-27, 2015
Southeastern Division Spring Meet Chair, April 9, 2016
Planning Sentimental Tour, June 12-17, 2016

67ss350camaro

  • CRG Member
  • *****
  • Posts: 159
    • View Profile
Re: 12 bolt applications
« Reply #3 on: November 29, 2006, 01:35:00 PM »
I know that it was possible to order a 3.73 rear end ratio (12 bolt) with a Powerglide in 67, but was it at all usual or even recommended?    3.73 strikes me as a bit aggressive for a 2-spd auto trans. 

We do have record of some L48/M35/3.73 combos in the data base, but not many.  But then, the 3.73 axle was not a high demand option to start with.  The 3.55 axle was much more popular.
Daniel
CRG
67 RS/SS 350 auto (owned since 81.)
97 V6 5-speed Coupe (work car ordered new)
2012 1LS (V6 6-speed) Coupe (new work car)
My Camaro

67 kemie ss

  • Member
  • ***
  • Posts: 35
    • View Profile
Re: 12 bolt applications
« Reply #4 on: December 01, 2006, 08:27:21 AM »
Gotta love this site.  OK Thanks guys.