4.11s are lousy for highway cruising. But if you are only going to take it out locally, from street light to street light you will love them. Expect terrible gas mileage at 60mph plus. I had 3.55s in my 67 351W C-4 and got about 10mpg at 65mph. Now that I've installed an AOD it's bumped up to 22-23mpg and only 2200rpm at 65mph.

 

Maybe I'll look for an overdrive transmission as well (I have a C-4)

Thanks for the reply

 

It also depends on how tall your tires are. Most drag cars have lower gears than 4.11, but they usually have pretty big tires.

 

I have 4:11 on my truck. real bad for highway...with Gear Vendors at 75 Mph I am at 2500 with deisel....My 66 has 3:00 and I run 2800 at 75 with C4. For off the line the 4:11 is the bomb, try a five speed with it for highway. Better for all around is the 3:55 and down. You tire hight matters but will not reduce the ratio down enough to compare to an overdrive gear.

 

I have 4:11 right now in my fastback. I'm hitting some serious rpm's even with the 275/60r15s in back. I believe that when I'm doing 70 mph, I'm up around 3600 rpm's. So, if you're going to be out on the freeway, I'd go to a taller gear like a 3:50.

 

I run 4:11's on my Fast Back... Only drive it in the city. Will not take it on the highway. I run 8" rubber; nice off the line and gears 1 through 4, top end @ about 1/4 mile so there are many disadvantages. Mileage, if you have to ask don't run 4;11's.

 

How are 4:11s on the highway? (RPMs etc.) Is is strictly a "drag race" gear?

Occasionally, they're fine. Lots of my street racing buddies ran them. I popped out the 3.50's and put in 4.62's for weekend street races and trips to the track (either on a trailer or flat-towed). If the engine is built right, it won't even blink at 4.11's and 3.5-4K at freeway speeds. It'll just wear out faster (more revolutions per mile)...

You'll also need to seriously consider suspension/traction issues...that's a lot of gear multiplication to be putting through street tires. I used J-bolt competition bars, a pinion snubber and drag racing shocks on my street racer. Worked pretty good with the C4 and 11" converter.

Have fun!

[color:white]camachinist</font color=white>

 

I run 4.62's with an AOD and my rpm's are reasonable. I think about 3K at highway speeds. Off the line is great!
-Brian

 

I've got 4.11s and they are ok with over drive and a 27" rear tire. Wouldn't even consider them otherwise... We drive pretty fast on the roads in AZ (something about the lack of snow) and you're always moving pretty good. I'm at 2500 RPM at 75 mph in 5th gear. Without over drive it would be around 3800 RPM, ouch.

 

I have 4.11 gear's in my 70 FB. with 275/60 15 T/A radials. FMX automatic. Going to the strip and back it is turning about 2800 at 55 MPH. If I was ever going to get on the interstate or/and drive a few hundred miles away much I diffently would not go lower than a 3.55 with the basic 3 speed automatic.

 

I read all the other posts and no-one mentioned going to something different. I have 3:70's in my 65 FB and love them. It's a good all-around gear, great in town, works well on the drag strip, it's not too hard on anything and the RPM's on the highway are liveable. Something to consider.

Doc the moneymanager
http://www.inficad.com/~moneymanager/shelbyracetrim.jpg

 

Doc,

Take a ride in Kindsford (maybe this Sunday) and it just might change your mind, hee hee.
Over drive is addicting, and the additional fuel milage doesn't hurt either /forums/images/icons/smile.gif