4l80e with 3.08 gears opinions

I got a chance to get a 4l80e... Idont know what to ask... If my math is close I came up with with final gear ratio of 2.40 17-1800RPM's at freeway speeds...

 

The 4l80e trans has been in production for 30 years and there ain't no shortage of them. You can easily find another.

That being said OD and 3.08s is a touch excessive but do able. You might only use OD over 60. If you have a radical cam it won't like to be lugged down.

 

I agree 3.08 are on the edge... 3.54 would be better.... I don't think my cam is too radical..

 

I run 3.73s with a 4l60. 70 is 2k
With a cam and it is perfect for me.

 

You guys are forgetting tire size and the final OD % for each transmission...Then are you talking lock up convertor number or just 4th gear no lock up??
WHAT rear are you using to know what other ratios are available...

 

In my case I'm running 225/70/14 at this point of time. With a 12bolt chevy

 

I am running 245 15s with lock up converter.

 

3.73

 

Having spent many years with a 2.56 rearend, I can assure you that our engines love low RPM's and I wish I'd had a combination like you describe (incl. the lockup) for even lower RPM's on the highway.

Although I have had EFI since 1993, I still think a carb would do well above 1500RPMs at the light throttle our engines require.

-Bob C.

 

The 1800 RPM my Tahoe cruises at with the 6 speed and 3.42 gear is a DOG!
I’m sure a 455 wouldn’t be as far as accelerating without a downshift at that RPM.
The LS’s are doggy unless you keep ‘em wound up.

 

Good thread as I'm looking for some help with my setup. 6.0 turbo LS, 4200lb Electra weighed on a truck scale, 31in tall tire, 4l60E trans for now, 3500 stall converter. I'm currently working with Quick performance to have them build me a rear-end. This is a street cruiser with occasional trips to the drag strip. Thoughts on what would be an all around good gear ratio? Thanks for the help

 

Thanks Larry

I my math was close to your answer..... Now I can't remember how I came up with my answer..

 

my 70 X stage-2 with a 4L80E has 3.55 gear and 305 rear tires. I just came back from a show about 60 miles away, all highway cruising. In 4th gear is 2400 to 2500 rpm. With the converter locked up, it drops about 200 to 250 rpm. It's hard to tell exactly but this is real close. Glancing over at the tach, that's about an average of 2300 rpm cruising 65 to 70 mph.

Fernando