Richard McLaughlin
1974 Duster 340
Where do I get those???sounds like a plan
perhaps, while the axles are out, you may want to upgrade the wheel studs as well
Where do I get those???sounds like a plan
perhaps, while the axles are out, you may want to upgrade the wheel studs as well
Thanks!Search member "webby" for a 3.91 complete set up.
After calculating my numbers accouting for the open defferential... I think i am at 3.23to find the gear ratio of the vehicle. Put the back up on jack stands. Put the car in nuetral. make a mark on the driveline or pinion yolk and on the inside of the tire where you will be able to keep track of revolutions. turn the drivline. keep track of how many time the driveline must turn to make one full revolution of the wheel. Done! 3.23 to 1. 3.91 to 1. etc. etc. etc.
Ok. I hope they are not like 3.73 or 3.91 and I did the swap for nothing! Should I look before ordering?When you swap gear sections out, look on the ring gears side for the ratio stamped in it.
You think I should buy from web by or dr diff?When you swap gear sections out, look on the ring gears side for the ratio stamped in it.
But I wana go fast!!!If I was drag racing all the time, the 3.91 gears would make sense. But, let's go over again how are you using this car.... You say 99% street but is this street racing? Or just cruising? If cruising, you are probably not going to be happy in the long term putting that amount of $$ into a 3.91 gear set that makes the car noisy and vibrates more at highway speeds, and drops gas mileage a lot. All of the engine operations will now be moved HIGHER in the RPM range, which is opposite of what you seemed to want to do earlier (post #24).
We have been talking about a lot of things but your use of the car keeps falling out of the picture. Bad advice and decisions flows from not clearly staying focused on what you will do with the car.
That is cool. My rear tire is 255/60/15. I was going to get 275/60/15 at some point. The 255 is 27" and the 275 is 28" - acording to a online tire height calculator.here is a chart that might help you out. i guest on tire height at 25"
sorry i made a mess of this but you can go on there sight and do some figuring on you one
Engine Speed (RPM) MPH 3.91 Gear MPH 3.23 Gear MPH 2.76 Gear
3500 RPM 66.58 MPH 3.91
3000 RPM 69.08 MPH 3.23
2500 RPM RPM/MPH From Gear Ratio Calculator by Wallace Racing
67.38 2.76
Here is the sight if you want to play around with gear ratio and tire size.
RPM/MPH From Gear Ratio Calculator by Wallace Racing
Click on that link i posted and play around with it........it will help you make a decision on tires as well as gear ratioThat is cool. My rear tire is 255/60/15. I was going to get 275/60/15 at some point. The 255 is 27" and the 275 is 28" - acording to a online tire height calculator.
Did you dislike your 3.91 or did you find it a good highway/street/strip balance?Click on that link i posted and play around with it........it will help you make a decision on tires as well as gear ratio
when i still ran my car on the street, i had 3.91 and 235/75/15 truck tire on the back and 26 slick that i raced at the track with.
Even with 28" tires you were the slow one on the freeway.
Perfect!If your not going this be on the Hwy. much, 3.91's are fine and with the tall tire, not to bad of a combo.
The "Good compromise" gear choices are 3.23 & 3.55. Normally MoPar's do not come with 3.73's. But those are the 3 ratios considered to fall into that category. And tire size (height) has a play in that as well.
I have run 4.10's for decades. I last had 255/60/15's out back and IMO, it was excellent for the build, car & performance intended. I had no issue being on the Hwy. Of course, I did not travel very fast. 60/65 mph was the cruise speed. The car was a manual and the tack ran around the 3300 area. I do not under any way consider that spinning the engine high for Hwy. driving for the build that it was and the set up it ran. A lot of people cry like they have a baby at that.
If that's to much for you.......
Did you dislike your 3.91 or did you find it a good highway/street/strip balance?
WeeeeeeeehooooooooThat will fit your application.
That is a good strong differential.
You will notice a big emprovment on your
"Get up and go "!
Rear gear selection is something that goes along with the use of the car. If ripping or tearing is what you want to do, then go high! Look at what YR uses: 4.56 LOL! The term street/strip gets used in a lot of different ways, and means different things to different people. So when I hear 'street/strip', I ask what the person really want to do.But I wana go fast!!!
I will not be doing much highway. Maybe once a year. I don't think I would mind the noise. My daily driver ram 1500 has 35 shaky tire and bro exhaust with no resonators.
However, I was under the impression that 3.91 is a good compromise for street/strip.
I have 4.88's in the Duster now. Put put around town and rip it up on the back street strip. Not really good for anything in between. But I do like them.The best street/strip compromise gear I've found is the tried and true 4.56. The perfect street strip gear. It's what I use.