12 bolt applications

[67 kemie ss]

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]

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.

[lakeholme]

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.

[67ss350camaro]

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.

[67 kemie ss]

Gotta love this site.  OK Thanks guys.