I love the low gears in my 442, but after a two hour highway drive this past week I'm seriously considering going to a more highway friendly gear. There must be a few of you who have made the switch and I welcome your thoughts. Oh yea, M-20 4 speed in the car and a fresh 455.
Ben

 

What axle do you have, Type O or Chevy 12 bolt? If it's a Type O, 3.23 gears may not be easy to find. Keep in mind that you'll need to change the carrier to a 3-series; 3.23 gears won't physically fit on a 4-series. You might want to consider 3.42s, which WILL fit on a 4-series carrier. The difference from 3.23 to 3.42 is negligible as far as highway RPMs are concerned.

 

Type O rear end with 28 spline axles.

 

Perhaps I should expand on my thoughts,
Option 1- move to a lower numerical gear.
Option 2- perhaps a gear vendor overdrive set-up.
Option 3-drop in a 5 speed trans.
My objective isn't really to modify my car so much as it is to make it more of an all around fun car for all situations, Bad *** off the line and a nice comfy cruiser. I would think I could have my cake and eat it too.

 

Many have tried and many have failed.

 

X2 on the 3.42 gears. I would for sure go with the 3.42 for all around

 

If you put in a lower numerical gear, you reduce off-the-line performance. A 3.42 will be like a 0.88 overdrive ratio.

If you put in 5-speed, a 6-speed, or a Gear Vendor overdrive, you will keep low-speed performance and the comfy cruiser vibe.

A 5-speed will give you a 0.64 overdrive and about 600 ft lb torque limit. You'll need to find one that has the same shifter position so you can use the factory console. You will need to cut a new hole in the tunnel for the shifter that comes off the top of the trans instead of the side. You'll need to adapt to the factory clutch linkage or install a hydraulic clutch, shorten the driveshaft, and reposition the trans crossmember.

A 6-speed will give a 0.50 overdrive and about 800 ft lb torque capacity. The unit is so big that you will need major tunnel surgery. The comments for the 5-speed also apply.

A Gear Vendors will give you a 0.78 overdrive ratio, has much more torque capacity than any Olds can muster, and is the cheapest of the three overdrive choices. You'll need to beat on the tunnel to add clearance where it pinches down behind the trans but a hard rubber mallet will usually work. The driveshaft needs to be shortened by 14 inches and change.

Overall, I think the GV is a much simpler solution and can be installed much more easily. Additionally, used units are often available if you want to save money.

 

Keep the 3.90
Unless you want to swap..lol
The 3.42 isnt worth the reduction, uld still want a overdrive unit like gear vendors

 

Overdrive units are...interesting. Back when they used to be a thing, separately, from the factory, you could engage them whenever you wanted. So, instead of 1,2,3,4 you could have 2,3,4,5 effectively with 4 gears. This would allow you Cruise Mode, and ***** Out Mode. I would think it would be interesting to do.

 

an even better option with no modifications would be to add an overdrive gear in place of fourth gear in your 4 speed trans as they are available in more than one overdrive ratio.

 

Not mine but thought I would pass it along

https://minneapolis.craigslist.org/d...939336291.html

Or you could change carrier and gears to 3.08 or 3.23

 

You can always build another rear with your choice of gear. Maybe a 71/72 corporate rear will give you more options and probably at a lower price.

Don W

 

olds 3.42 are like 3.41 if I recall but 3.23 are not 3.23 they call them that they are 3.15s or something like that. I just made that swap but no drive time yet

 

Not really sure where you got this information, but it's incorrect. Take a good look down the left side for the gear ratios and the tooth count on the ring and pinion. A 3.23 is a 3.23.

 

from doing the math with the gear count
But not sure how I screwed it up i used my phone as a calculator

 

I'm going to have to pull the cover and do it again at only sucks because I just put new fluid in it

 

The Type O 3.23 gears have a 42 tooth ring gear and a 13 tooth pinion. 42/13 = 3.230769

 

but from what I still have chicken scratched down is 41 and 13

 

Dividing gear counts and comparing to nominal ratios, two gears differ by -1 in the third significant figure:

• 2.78 is actually 2.79
• 4.66 is actually 4.67

The others are spot on.

 

From the parts book:

 

39/14 = 2.78571, so yeah, someone didn't round off properly.
42/9 = 4.666666666

Heck, even the IRS lets you round to the nearest dollar.

 

The 2.78 was originally designed with a 38.5 tooth ring gear, but they wore out too fast.
The 39 tooth ran much quieter & lasted longer.....

 

Now that is funny!