I emailed the guy i bought my tranny from, which was supposedly a std 72 4-speed, but it turned out to be a 76 cast iron OD. He said he would bring me the right tranny no charge. So, std. or OD? Same price . Which is better? I do mostly street driving w/ a little on the freeway.

tommyb1515@aol.com

Which "standard" 1 to 1 tranny does he have?
The "close ratio" (2.65 first) or the "wide ratio" (3.09 first) unit?

For your SL6 you want the 3.09 first so you need to ask him what he has.
DD

thanks Doc, i e-mailed him and still waiting for a reply. Can i swap the gears from the 2 trannys to make a tranny w/3.09 1st and 1:1 fourth?

Thanks, Tom B

The factory offered the 3.09 / 1 to 1 tranny.
SL6 and 318 cars used it, the mucle cars used the close ratio box.
It is best to get the correct trans to begain with so see what he has.
DD

So Doug, uh, I mean Doc, you recommend the O.D. manual trans over the close ratio 4-speed?

Wes
a.k.a. Wesola78

wes.moeller@compaq.com

Errrrr....it depends on the combo and what you want to do with the car.
Here is how I use the different ratio 833s:

OD unit for a general purpose street car where you want good off the line (3.09 first) and great highway cruzing. (.73 overdrive) I feel these OD units work best with a 3.91 rearend ratio but I bet that new 3.7? ratio offered by Randy's R&P would better.
(11.55 start-off ratio, 2.73 final - OD)

The 3.09 - 1 to 1 final 833 is a good "street / strip" unit for a Slant. Highway cruze starts to suffer on this one. Rearend ratio of 3.23 is about as low as I can stand on the highway. I usually run a 2.94 behind this box and put up with the somewhat "lazy" 9.08 start-off ratio that results.

The close ratio (2.66 first) box is not a good choice for a street slant. These are great for racers, 1/4 mile or road course. You need to run a 3.91 rear to get a 10.4 start-off ratio. (that new 3.7? gives a 9.94 start-off) but these low rearend ratios suck on the open road. (suck gas and "ring" your ears) The "super-close ratio" 2.47 "TA box" is even worse when it come to getting the car to move from a standing start.
(2.47 x 3.91 = 9.65 start-off ratio)
(2.47 x 3.55 = 8.77 . . .)

See the ratio chart below, happy shifting : - )
DD

Thanks for the guidleines Doug, i decided to keep the over drive tranny, its pretty cool going down the freeway at 80 mph in 4-th at only about 200 rpms. I eventually want to get an 8.25" rear with some 3.55's or 3.73's. with the 3.73's+OD the final drive ratio would be about the same as 2.76 gears and a 1:1 4-th.

tommyb1515@aol.com

Thanks again, Doc! I "thought" I had an A833 out of a "matching numbers" 71 Challanger. I'm reading this and thinking "on stink" I got the wrong darn trans. Well, it is a 3:09-1:00. Whew. Now I do have a 3.91/Suregrip 8.75" that I'm planning to run. This is going to be street / strip. The 12.08 first gear should be a real kick in the butt off the line.

Later,

Gilly

tlg225ccr@aol.com

Here's a nifty little calculator I found on the web. The numbers are for my combo. Looks like we'll be running around 3300 @ 65 mph and 5000 @ 100 mph. That should work, yeah....

Plug in your own numbers and see what comes out.

Gilly

Ratio Calculator
tlg225ccr@aol.com